diff --git a/datafusion/core/src/physical_planner.rs b/datafusion/core/src/physical_planner.rs
index 132bc3953cd3..d4a9a949fc41 100644
--- a/datafusion/core/src/physical_planner.rs
+++ b/datafusion/core/src/physical_planner.rs
@@ -276,9 +276,6 @@ fn create_physical_name(e: &Expr, is_first_expr: bool) -> Result<String> {
                     .collect::<Result<Vec<_>>>()?;
                 Ok(format!("{}({})", fun.name(), names.join(",")))
             }
-            AggregateFunctionDefinition::Name(_) => {
-                internal_err!("Aggregate function `Expr` with name should be resolved.")
-            }
         },
         Expr::GroupingSet(grouping_set) => match grouping_set {
             GroupingSet::Rollup(exprs) => Ok(format!(
@@ -1947,11 +1944,6 @@ pub fn create_aggregate_expr_with_name_and_maybe_filter(
                     )?;
                     (agg_expr, filter, physical_sort_exprs)
                 }
-                AggregateFunctionDefinition::Name(_) => {
-                    return internal_err!(
-                        "Aggregate function name should have been resolved"
-                    )
-                }
             };
             Ok((agg_expr, filter, order_by))
         }
diff --git a/datafusion/expr/src/expr.rs b/datafusion/expr/src/expr.rs
index 01ef2571ea82..ed55b7b3c24e 100644
--- a/datafusion/expr/src/expr.rs
+++ b/datafusion/expr/src/expr.rs
@@ -515,9 +515,6 @@ pub enum AggregateFunctionDefinition {
     BuiltIn(aggregate_function::AggregateFunction),
     /// Resolved to a user defined aggregate function
     UDF(Arc<crate::AggregateUDF>),
-    /// A aggregation function constructed with name. This variant can not be executed directly
-    /// and instead must be resolved to one of the other variants prior to physical planning.
-    Name(Arc<str>),
 }
 
 impl AggregateFunctionDefinition {
@@ -526,7 +523,6 @@ impl AggregateFunctionDefinition {
         match self {
             AggregateFunctionDefinition::BuiltIn(fun) => fun.name(),
             AggregateFunctionDefinition::UDF(udf) => udf.name(),
-            AggregateFunctionDefinition::Name(func_name) => func_name.as_ref(),
         }
     }
 }
@@ -1829,8 +1825,7 @@ pub(crate) fn create_name(e: &Expr) -> Result<String> {
             null_treatment,
         }) => {
             let name = match func_def {
-                AggregateFunctionDefinition::BuiltIn(..)
-                | AggregateFunctionDefinition::Name(..) => {
+                AggregateFunctionDefinition::BuiltIn(..) => {
                     create_function_name(func_def.name(), *distinct, args)?
                 }
                 AggregateFunctionDefinition::UDF(..) => {
@@ -1850,8 +1845,7 @@ pub(crate) fn create_name(e: &Expr) -> Result<String> {
                 info += &format!(" {}", nt);
             }
             match func_def {
-                AggregateFunctionDefinition::BuiltIn(..)
-                | AggregateFunctionDefinition::Name(..) => {
+                AggregateFunctionDefinition::BuiltIn(..) => {
                     Ok(format!("{}{}", name, info))
                 }
                 AggregateFunctionDefinition::UDF(fun) => {
diff --git a/datafusion/expr/src/expr_schema.rs b/datafusion/expr/src/expr_schema.rs
index 4aca52d67c4f..8b07c556fefc 100644
--- a/datafusion/expr/src/expr_schema.rs
+++ b/datafusion/expr/src/expr_schema.rs
@@ -173,9 +173,6 @@ impl ExprSchemable for Expr {
                     AggregateFunctionDefinition::UDF(fun) => {
                         Ok(fun.return_type(&data_types)?)
                     }
-                    AggregateFunctionDefinition::Name(_) => {
-                        internal_err!("Function `Expr` with name should be resolved.")
-                    }
                 }
             }
             Expr::Not(_)
diff --git a/datafusion/expr/src/tree_node.rs b/datafusion/expr/src/tree_node.rs
index 710164eca3d0..1b3b5e8fcb83 100644
--- a/datafusion/expr/src/tree_node.rs
+++ b/datafusion/expr/src/tree_node.rs
@@ -27,7 +27,7 @@ use crate::{Expr, GetFieldAccess};
 use datafusion_common::tree_node::{
     Transformed, TreeNode, TreeNodeIterator, TreeNodeRecursion,
 };
-use datafusion_common::{internal_err, map_until_stop_and_collect, Result};
+use datafusion_common::{map_until_stop_and_collect, Result};
 
 impl TreeNode for Expr {
     fn apply_children<F: FnMut(&Self) -> Result<TreeNodeRecursion>>(
@@ -348,9 +348,6 @@ impl TreeNode for Expr {
                             null_treatment,
                         )))
                     }
-                    AggregateFunctionDefinition::Name(_) => {
-                        internal_err!("Function `Expr` with name should be resolved.")
-                    }
                 },
             )?,
             Expr::GroupingSet(grouping_set) => match grouping_set {
diff --git a/datafusion/optimizer/src/analyzer/type_coercion.rs b/datafusion/optimizer/src/analyzer/type_coercion.rs
index 61b1d1d77b20..8130e09e2989 100644
--- a/datafusion/optimizer/src/analyzer/type_coercion.rs
+++ b/datafusion/optimizer/src/analyzer/type_coercion.rs
@@ -353,9 +353,6 @@ impl<'a> TreeNodeRewriter for TypeCoercionRewriter<'a> {
                         ),
                     )))
                 }
-                AggregateFunctionDefinition::Name(_) => {
-                    internal_err!("Function `Expr` with name should be resolved.")
-                }
             },
             Expr::WindowFunction(WindowFunction {
                 fun,
diff --git a/datafusion/optimizer/src/decorrelate.rs b/datafusion/optimizer/src/decorrelate.rs
index a6abec9efd8c..3959223e68c1 100644
--- a/datafusion/optimizer/src/decorrelate.rs
+++ b/datafusion/optimizer/src/decorrelate.rs
@@ -398,9 +398,6 @@ fn agg_exprs_evaluation_result_on_empty_batch(
                         AggregateFunctionDefinition::UDF { .. } => {
                             Transformed::yes(Expr::Literal(ScalarValue::Null))
                         }
-                        AggregateFunctionDefinition::Name(_) => {
-                            Transformed::yes(Expr::Literal(ScalarValue::Null))
-                        }
                     },
                     _ => Transformed::no(expr),
                 };
diff --git a/datafusion/proto/src/logical_plan/to_proto.rs b/datafusion/proto/src/logical_plan/to_proto.rs
index 80acd12e4e60..a18f0eb01bb3 100644
--- a/datafusion/proto/src/logical_plan/to_proto.rs
+++ b/datafusion/proto/src/logical_plan/to_proto.rs
@@ -750,12 +750,6 @@ pub fn serialize_expr(
                     },
                 ))),
             },
-            AggregateFunctionDefinition::Name(_) => {
-                return Err(Error::NotImplemented(
-                    "Proto serialization error: Trying to serialize a unresolved function"
-                        .to_string(),
-                ));
-            }
         },
 
         Expr::ScalarVariable(_, _) => {
diff --git a/datafusion/substrait/src/logical_plan/producer.rs b/datafusion/substrait/src/logical_plan/producer.rs
index 39b2b0aa1606..db5d341bc225 100644
--- a/datafusion/substrait/src/logical_plan/producer.rs
+++ b/datafusion/substrait/src/logical_plan/producer.rs
@@ -733,9 +733,6 @@ pub fn to_substrait_agg_measure(
                         }
                     })
                 }
-                AggregateFunctionDefinition::Name(name) => {
-                    internal_err!("AggregateFunctionDefinition::Name({:?}) should be resolved during `AnalyzerRule`", name)
-                }
             }
 
         }