diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5560a1fead..cd3746d92b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@
 
 * ![Bugfix][badge-bugfix] When including docstrings for an alias, Documenter now correctly tries to include the exactly matching docstring first, before checking for signature subtypes. ([#1842][github-1842])
 * ![Bugfix][badge-bugfix] When checking for missing docstrings, Documenter now correctly handles docstrings for methods that extend bindings from other modules that have not been imported into the current module. ([#1695][github-1695], [#1857][github-1857], [#1861][github-1861])
+* ![Bugfix][badge-bugfix] By overriding `GIT_TEMPLATE_DIR`, `git` no longer picks up arbitrary user templates and hooks when internally called by Documenter. ([#1862][github-1862])
 
 ## Version `v0.27.19`
 
@@ -1083,6 +1084,7 @@
 [github-1846]: https://github.com/JuliaDocs/Documenter.jl/pull/1846
 [github-1857]: https://github.com/JuliaDocs/Documenter.jl/issues/1857
 [github-1861]: https://github.com/JuliaDocs/Documenter.jl/pull/1861
+[github-1862]: https://github.com/JuliaDocs/Documenter.jl/pull/1862
 <!-- end of issue link definitions -->
 
 [julia-38079]: https://github.com/JuliaLang/julia/issues/38079
diff --git a/src/Documenter.jl b/src/Documenter.jl
index c801d279c8..5303e1d452 100644
--- a/src/Documenter.jl
+++ b/src/Documenter.jl
@@ -61,7 +61,7 @@ include("CrossReferences.jl")
 include("DocChecks.jl")
 include("Writers/Writers.jl")
 
-import .Utilities: Selectors
+import .Utilities: Selectors, git
 import .Writers.HTMLWriter: HTML, asset
 import .Writers.HTMLWriter.RD: KaTeX, MathJax, MathJax2, MathJax3
 import .Writers.LaTeXWriter: LaTeX
@@ -564,7 +564,7 @@ function deploydocs(;
             # the working directory has been changed (e.g. if the makedocs' build argument is
             # outside root).
             sha = try
-                readchomp(`git rev-parse --short HEAD`)
+                readchomp(`$(git()) rev-parse --short HEAD`)
             catch
                 # git rev-parse will throw an error and return code 128 if it is not being
                 # run in a git repository, which will make run/readchomp throw an exception.
@@ -618,17 +618,17 @@ function git_push(
     # Generate a closure with common commands for ssh and https
     function git_commands(sshconfig=nothing)
         # Setup git.
-        run(`git init`)
-        run(`git config user.name "Documenter.jl"`)
-        run(`git config user.email "documenter@juliadocs.github.io"`)
+        run(`$(git()) init`)
+        run(`$(git()) config user.name "Documenter.jl"`)
+        run(`$(git()) config user.email "documenter@juliadocs.github.io"`)
         if sshconfig !== nothing
-            run(`git config core.sshCommand "ssh -F $(sshconfig)"`)
+            run(`$(git()) config core.sshCommand "ssh -F $(sshconfig)"`)
         end
 
         # Fetch from remote and checkout the branch.
-        run(`git remote add upstream $upstream`)
+        run(`$(git()) remote add upstream $upstream`)
         try
-            run(`git fetch upstream`)
+            run(`$(git()) fetch upstream`)
         catch e
             @error """
             Git failed to fetch $upstream
@@ -640,7 +640,7 @@ function git_push(
         end
 
         try
-            run(`git checkout -b $branch upstream/$branch`)
+            run(`$(git()) checkout -b $branch upstream/$branch`)
         catch e
             @info """
             Checking out $branch failed, creating a new orphaned branch.
@@ -649,8 +649,8 @@ function git_push(
             from Git in this situation.
             """
             @debug "checking out $branch failed with error: $e"
-            run(`git checkout --orphan $branch`)
-            run(`git commit --allow-empty -m "Initial empty commit for docs"`)
+            run(`$(git()) checkout --orphan $branch`)
+            run(`$(git()) commit --allow-empty -m "Initial empty commit for docs"`)
         end
 
         # Copy docs to `subfolder` directory.
@@ -691,14 +691,14 @@ function git_push(
         end
 
         # Add, commit, and push the docs to the remote.
-        run(`git add -A .`)
-        if !success(`git diff --cached --exit-code`)
+        run(`$(git()) add -A .`)
+        if !success(`$(git()) diff --cached --exit-code`)
             if forcepush
-                run(`git commit --amend --date=now -m "build based on $sha"`)
-                run(`git push -fq upstream HEAD:$branch`)
+                run(`$(git()) commit --amend --date=now -m "build based on $sha"`)
+                run(`$(git()) push -fq upstream HEAD:$branch`)
             else
-                run(`git commit -m "build based on $sha"`)
-                run(`git push -q upstream HEAD:$branch`)
+                run(`$(git()) commit -m "build based on $sha"`)
+                run(`$(git()) push -q upstream HEAD:$branch`)
             end
         else
             @debug "new docs identical to the old -- not committing nor pushing."
@@ -820,7 +820,7 @@ function gitrm_copy(src, dst)
     if isdir(dst)
         for x in filter!(!in((".git", "previews")), readdir(dst))
             # --ignore-unmatch so that we wouldn't get errors if dst does not exist
-            run(`git rm -rf --ignore-unmatch $(joinpath(dst, x))`)
+            run(`$(git()) rm -rf --ignore-unmatch $(joinpath(dst, x))`)
         end
     end
     # git rm also remove parent directories
diff --git a/src/Utilities/Utilities.jl b/src/Utilities/Utilities.jl
index 30e45c025c..2bd1f660e2 100644
--- a/src/Utilities/Utilities.jl
+++ b/src/Utilities/Utilities.jl
@@ -425,7 +425,7 @@ end
 
 function repo_commit(file)
     cd(dirname(file)) do
-        readchomp(`git rev-parse HEAD`)
+        readchomp(`$(git()) rev-parse HEAD`)
     end
 end
 
@@ -515,7 +515,7 @@ const GIT_REMOTE_CACHE = Dict{String,String}()
 function getremote(dir::AbstractString)
     return get!(GIT_REMOTE_CACHE, dir) do
         remote = try
-            readchomp(setenv(`git config --get remote.origin.url`; dir=dir))
+            readchomp(setenv(`$(git()) config --get remote.origin.url`; dir=dir))
         catch
             ""
         end
@@ -531,7 +531,7 @@ Returns the first 5 characters of the current git commit hash of the directory `
 """
 function get_commit_short(dir)
     commit = cd(dir) do
-        readchomp(`git rev-parse HEAD`)
+        readchomp(`$(git()) rev-parse HEAD`)
     end
     (length(commit) > 5) ? commit[1:5] : commit
 end
@@ -790,13 +790,16 @@ it out automatically.
 to construct the warning messages.
 """
 function git_remote_head_branch(varname, root; remotename = "origin", fallback = "master")
-    env = copy(ENV)
-    env["GIT_TERMINAL_PROMPT"] = "0"
-    env["GIT_SSH_COMMAND"] = get(env, "GIT_SSH_COMMAND", "ssh -o \"BatchMode yes\"")
-    cmd = `git remote show $(remotename)`
+    # We need to do addenv() here to merge the new variables with the environment set by
+    # Git_jll and the git() function.
+    cmd = addenv(
+        setenv(`$(git()) remote show $(remotename)`, dir=root),
+        "GIT_TERMINAL_PROMPT" => "0",
+        "GIT_SSH_COMMAND" => get(ENV, "GIT_SSH_COMMAND", "ssh -o \"BatchMode yes\""),
+    )
     stderr_output = IOBuffer()
     git_remote_output = try
-        read(pipeline(setenv(cmd, env; dir=root); stderr = stderr_output), String)
+        read(pipeline(cmd; stderr = stderr_output), String)
     catch e
         @warn """
         Unable to determine $(varname) from remote HEAD branch, defaulting to "$(fallback)".
@@ -846,6 +849,15 @@ dropheaders(h::Markdown.Header) = Markdown.Paragraph([Markdown.Bold(h.text)])
 dropheaders(v::Vector) = map(dropheaders, v)
 dropheaders(other) = other
 
+function git(; kwargs...)
+    system_git_path = Sys.which("git")
+    isnothing(system_git_path) && error("Unable to find `git`")
+    # According to the Git man page, the default GIT_TEMPLATE_DIR is at /usr/share/git-core/templates
+    # We need to set this to something so that Git wouldn't pick up the user
+    # templates (e.g. from init.templateDir config).
+    return addenv(`$(system_git_path)`, "GIT_TEMPLATE_DIR" => "/usr/share/git-core/templates")
+end
+
 include("DOM.jl")
 include("MDFlatten.jl")
 include("TextDiff.jl")
diff --git a/test/doctests/doctests.jl b/test/doctests/doctests.jl
index 1285098973..ec06c4e15b 100644
--- a/test/doctests/doctests.jl
+++ b/test/doctests/doctests.jl
@@ -34,13 +34,17 @@ function run_makedocs(f, mdfiles, modules=Module[]; kwargs...)
     touch(joinpath(srcdir, "index.md"))
 
     c = IOCapture.capture(rethrow = InterruptException) do
-        makedocs(
-            sitename = " ",
-            format = Documenter.HTML(edit_link = "master"),
-            root = dir,
-            modules = modules;
-            kwargs...
-        )
+        # In case JULIA_DEBUG is set to something, we'll override that, so that we wouldn't
+        # get some unexpected debug output from makedocs.
+        withenv("JULIA_DEBUG" => "") do
+            makedocs(
+                sitename = " ",
+                format = Documenter.HTML(edit_link = "master"),
+                root = dir,
+                modules = modules;
+                kwargs...
+            )
+        end
     end
 
     @debug """run_makedocs($mdfiles, modules=$modules) -> $(c.error ? "fail" : "success")
diff --git a/test/utilities.jl b/test/utilities.jl
index 69d909440b..8a30ff3dfc 100644
--- a/test/utilities.jl
+++ b/test/utilities.jl
@@ -1,10 +1,12 @@
 module UtilitiesTests
 
 using Test
+using Logging: Info
 import Base64: stringmime
 include("TestUtilities.jl"); using .TestUtilities
 
 import Documenter
+using Documenter.Utilities: git
 import Markdown
 
 module UnitTests
@@ -166,15 +168,15 @@ end
         mkpath(path_repo)
         cd(path_repo) do
             # Create a simple mock repo in a temporary directory with a single file.
-            @test trun(`git init`)
-            @test trun(`git config user.email "tester@example.com"`)
-            @test trun(`git config user.name "Test Committer"`)
-            @test trun(`git remote add origin git@github.com:JuliaDocs/Documenter.jl.git`)
+            @test trun(`$(git()) init`)
+            @test trun(`$(git()) config user.email "tester@example.com"`)
+            @test trun(`$(git()) config user.name "Test Committer"`)
+            @test trun(`$(git()) remote add origin git@github.com:JuliaDocs/Documenter.jl.git`)
             mkpath("src")
             filepath = abspath(joinpath("src", "SourceFile.jl"))
             write(filepath, "X")
-            @test trun(`git add -A`)
-            @test trun(`git commit -m"Initial commit."`)
+            @test trun(`$(git()) add -A`)
+            @test trun(`$(git()) commit -m"Initial commit."`)
 
             # Run tests
             commit = Documenter.Utilities.repo_commit(filepath)
@@ -194,7 +196,7 @@ end
         # Test worktree
         path_worktree = joinpath(path, "worktree")
         cd("$(path_repo)") do
-            @test trun(`git worktree add $(path_worktree)`)
+            @test trun(`$(git()) worktree add $(path_worktree)`)
         end
         cd("$(path_worktree)") do
             filepath = abspath(joinpath("src", "SourceFile.jl"))
@@ -217,15 +219,15 @@ end
         path_submodule = joinpath(path, "submodule")
         mkpath(path_submodule)
         cd(path_submodule) do
-            @test trun(`git init`)
-            @test trun(`git config user.email "tester@example.com"`)
-            @test trun(`git config user.name "Test Committer"`)
+            @test trun(`$(git()) init`)
+            @test trun(`$(git()) config user.email "tester@example.com"`)
+            @test trun(`$(git()) config user.name "Test Committer"`)
             # NOTE: the target path in the `git submodule add` command is necessary for
             # Windows builds, since otherwise Git claims that the path is in a .gitignore
             # file.
-            @test trun(`git submodule add $(path_repo) repository`)
-            @test trun(`git add -A`)
-            @test trun(`git commit -m"Initial commit."`)
+            @test trun(`$(git()) submodule add $(path_repo) repository`)
+            @test trun(`$(git()) add -A`)
+            @test trun(`$(git()) commit -m"Initial commit."`)
         end
         path_submodule_repo = joinpath(path, "submodule", "repository")
         @test isdir(path_submodule_repo)
@@ -540,7 +542,7 @@ end
 
         function git_create_bare_repo(path; head = nothing)
             mkdir(path)
-            @test trun(`git -C $(path) init --bare`)
+            @test trun(`$(git()) -C $(path) init --bare`)
             @test isfile(joinpath(path, "HEAD"))
             if head !== nothing
                 write(joinpath(path, "HEAD"), """
@@ -551,34 +553,36 @@ end
                 # We need to commit something to the non-standard branch to actually
                 # "activate" the non-standard HEAD:
                 head = (head === nothing) ? "master" : head
-                @test trun(`git clone $(path) $(subdir_path)`)
-                @test trun(`git -C $(subdir_path) config user.email "tester@example.com"`)
-                @test trun(`git -C $(subdir_path) config user.name "Test Committer"`)
-                @test trun(`git -C $(subdir_path) checkout -b $(head)`)
-                @test trun(`git -C $(subdir_path) commit --allow-empty -m"initial empty commit"`)
-                @test trun(`git -C $(subdir_path) push --set-upstream origin $(head)`)
+                @test trun(`$(git()) clone $(path) $(subdir_path)`)
+                @test trun(`$(git()) -C $(subdir_path) config user.email "tester@example.com"`)
+                @test trun(`$(git()) -C $(subdir_path) config user.name "Test Committer"`)
+                @test trun(`$(git()) -C $(subdir_path) checkout -b $(head)`)
+                @test trun(`$(git()) -C $(subdir_path) commit --allow-empty -m"initial empty commit"`)
+                @test trun(`$(git()) -C $(subdir_path) push --set-upstream origin $(head)`)
             end
         end
 
         mktempdir() do path
             cd(path) do
+                # Note: running @test_logs with match_mode=:any here so that the tests would
+                # also pass when e.g. JULIA_DEBUG=Documenter when the tests are being run.
                 # If there is no parent remote repository, we should get a warning and the fallback value:
-                @test (@test_logs (:warn,) Documenter.Utilities.git_remote_head_branch(".", pwd(); fallback = "fallback")) == "fallback"
-                @test (@test_logs (:warn,) Documenter.Utilities.git_remote_head_branch(".", pwd())) == "master"
+                @test (@test_logs (:warn,) match_mode=:any Documenter.Utilities.git_remote_head_branch(".", pwd(); fallback = "fallback")) == "fallback"
+                @test (@test_logs (:warn,) match_mode=:any Documenter.Utilities.git_remote_head_branch(".", pwd())) == "master"
                 # We'll set up two "remote" bare repositories with non-standard HEADs:
                 git_create_bare_repo("barerepo", head = "maindevbranch")
                 git_create_bare_repo("barerepo_other", head = "main")
                 # Clone barerepo and test git_remote_head_branch:
-                @test trun(`git clone barerepo/ local/`)
+                @test trun(`$(git()) clone barerepo/ local/`)
                 @test Documenter.Utilities.git_remote_head_branch(".", "local") == "maindevbranch"
                 # Now, let's add the other repo as another remote, and fetch the HEAD for that:
-                @test trun(`git -C local/ remote add other ../barerepo_other/`)
-                @test trun(`git -C local/ fetch other`)
+                @test trun(`$(git()) -C local/ remote add other ../barerepo_other/`)
+                @test trun(`$(git()) -C local/ fetch other`)
                 @test Documenter.Utilities.git_remote_head_branch(".", "local") == "maindevbranch"
                 @test Documenter.Utilities.git_remote_head_branch(".", "local"; remotename = "other") == "main"
                 # Asking for a nonsense remote should also warn and drop back to fallback:
-                @test (@test_logs (:warn,) Documenter.Utilities.git_remote_head_branch(".", pwd(); remotename = "nonsense", fallback = "fallback")) == "fallback"
-                @test (@test_logs (:warn,) Documenter.Utilities.git_remote_head_branch(".", pwd(); remotename = "nonsense")) == "master"
+                @test (@test_logs (:warn,) match_mode=:any Documenter.Utilities.git_remote_head_branch(".", pwd(); remotename = "nonsense", fallback = "fallback")) == "fallback"
+                @test (@test_logs (:warn,) match_mode=:any Documenter.Utilities.git_remote_head_branch(".", pwd(); remotename = "nonsense")) == "master"
             end
         end
     end