diff --git a/pkg/sql/add_column.go b/pkg/sql/add_column.go
index cee5cbcda560..ba3e9aaccffa 100644
--- a/pkg/sql/add_column.go
+++ b/pkg/sql/add_column.go
@@ -206,6 +206,17 @@ func (p *planner) addColumnImpl(
 		}
 	}
 
+	if col.Virtual && !col.Nullable {
+		colName := tree.Name(col.Name)
+		newCol, err := n.tableDesc.FindColumnWithName(colName)
+		if err != nil {
+			return errors.NewAssertionErrorWithWrappedErrf(err, "failed to find newly added column %v", colName)
+		}
+		if err := addNotNullConstraintMutationForCol(n.tableDesc, newCol); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
diff --git a/pkg/sql/alter_table.go b/pkg/sql/alter_table.go
index 1d4248c3b4e8..9681f7b6cc5f 100644
--- a/pkg/sql/alter_table.go
+++ b/pkg/sql/alter_table.go
@@ -998,17 +998,9 @@ func applyColumnMutation(
 			}
 		}
 
-		info, err := tableDesc.GetConstraintInfo()
-		if err != nil {
+		if err := addNotNullConstraintMutationForCol(tableDesc, col); err != nil {
 			return err
 		}
-		inuseNames := make(map[string]struct{}, len(info))
-		for k := range info {
-			inuseNames[k] = struct{}{}
-		}
-		check := tabledesc.MakeNotNullCheckConstraint(col.GetName(), col.GetID(), tableDesc.GetNextConstraintID(), inuseNames, descpb.ConstraintValidity_Validating)
-		tableDesc.AddNotNullMutation(check, descpb.DescriptorMutation_ADD)
-		tableDesc.NextConstraintID++
 
 	case *tree.AlterTableDropNotNull:
 		if col.IsNullable() {
@@ -1065,6 +1057,21 @@ func applyColumnMutation(
 	return nil
 }
 
+func addNotNullConstraintMutationForCol(tableDesc *tabledesc.Mutable, col catalog.Column) error {
+	info, err := tableDesc.GetConstraintInfo()
+	if err != nil {
+		return err
+	}
+	inuseNames := make(map[string]struct{}, len(info))
+	for k := range info {
+		inuseNames[k] = struct{}{}
+	}
+	check := tabledesc.MakeNotNullCheckConstraint(col.GetName(), col.GetID(), tableDesc.GetNextConstraintID(), inuseNames, descpb.ConstraintValidity_Validating)
+	tableDesc.AddNotNullMutation(check, descpb.DescriptorMutation_ADD)
+	tableDesc.NextConstraintID++
+	return nil
+}
+
 func labeledRowValues(cols []catalog.Column, values tree.Datums) string {
 	var s bytes.Buffer
 	for i := range cols {
diff --git a/pkg/sql/logictest/testdata/logic_test/virtual_columns b/pkg/sql/logictest/testdata/logic_test/virtual_columns
index 80533aeab439..10a3cfb53718 100644
--- a/pkg/sql/logictest/testdata/logic_test/virtual_columns
+++ b/pkg/sql/logictest/testdata/logic_test/virtual_columns
@@ -1312,3 +1312,27 @@ CREATE TABLE public.t_added (
 
 statement ok
 DROP TABLE t_added
+
+# Regression test for #81675. The schema change logic must validate that
+# NOT NULL virtual columns indeed validate to non-NULL values for the existing
+# data in the table.
+subtest adding_not_null_virtual_column_validates_81675
+
+statement ok
+CREATE TABLE t81675 (i INT);
+INSERT INTO t81675 VALUES (1), (2), (NULL)
+
+statement ok
+ALTER TABLE t81675 ADD COLUMN j INT GENERATED ALWAYS AS (i+1) VIRTUAL;
+
+statement ok
+ALTER TABLE t81675 DROP COLUMN j;
+
+# Note that the pgcode here ought to be 23502 (not null violation) but is
+# instead 23514 (check constraint violation) because of implementation details.
+onlyif config local-legacy-schema-changer
+statement error pgcode 23514 validation of NOT NULL constraint failed
+ALTER TABLE t81675 ADD COLUMN j INT GENERATED ALWAYS AS (i+1) VIRTUAL NOT NULL;
+
+statement ok
+DROP TABLE t81675;