diff --git a/.changelog/30360.txt b/.changelog/30360.txt
new file mode 100644
index 000000000000..ed88e90857c4
--- /dev/null
+++ b/.changelog/30360.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_scheduler_schedule: Mark `arn` property of `dead_letter_config` as a required property
+```
diff --git a/internal/service/scheduler/flex.go b/internal/service/scheduler/flex.go
index e6a904d57dfd..e98f3038af6f 100644
--- a/internal/service/scheduler/flex.go
+++ b/internal/service/scheduler/flex.go
@@ -103,7 +103,7 @@ func expandECSParameters(ctx context.Context, tfMap map[string]interface{}) *typ
 		a.LaunchType = types.LaunchType(v)
 	}
 
-	if v, ok := tfMap["network_configuration"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["network_configuration"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.NetworkConfiguration = expandNetworkConfiguration(v[0].(map[string]interface{}))
 	}
 
@@ -611,15 +611,15 @@ func expandTarget(ctx context.Context, tfMap map[string]interface{}) *types.Targ
 		a.Arn = aws.String(v)
 	}
 
-	if v, ok := tfMap["dead_letter_config"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["dead_letter_config"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.DeadLetterConfig = expandDeadLetterConfig(v[0].(map[string]interface{}))
 	}
 
-	if v, ok := tfMap["ecs_parameters"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["ecs_parameters"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.EcsParameters = expandECSParameters(ctx, v[0].(map[string]interface{}))
 	}
 
-	if v, ok := tfMap["eventbridge_parameters"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["eventbridge_parameters"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.EventBridgeParameters = expandEventBridgeParameters(v[0].(map[string]interface{}))
 	}
 
@@ -627,7 +627,7 @@ func expandTarget(ctx context.Context, tfMap map[string]interface{}) *types.Targ
 		a.Input = aws.String(v)
 	}
 
-	if v, ok := tfMap["kinesis_parameters"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["kinesis_parameters"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.KinesisParameters = expandKinesisParameters(v[0].(map[string]interface{}))
 	}
 
@@ -635,15 +635,15 @@ func expandTarget(ctx context.Context, tfMap map[string]interface{}) *types.Targ
 		a.RoleArn = aws.String(v)
 	}
 
-	if v, ok := tfMap["retry_policy"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["retry_policy"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.RetryPolicy = expandRetryPolicy(v[0].(map[string]interface{}))
 	}
 
-	if v, ok := tfMap["sagemaker_pipeline_parameters"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["sagemaker_pipeline_parameters"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.SageMakerPipelineParameters = expandSageMakerPipelineParameters(v[0].(map[string]interface{}))
 	}
 
-	if v, ok := tfMap["sqs_parameters"].([]interface{}); ok && len(v) > 0 {
+	if v, ok := tfMap["sqs_parameters"].([]interface{}); ok && len(v) > 0 && v[0] != nil {
 		a.SqsParameters = expandSQSParameters(v[0].(map[string]interface{}))
 	}
 
diff --git a/internal/service/scheduler/schedule.go b/internal/service/scheduler/schedule.go
index 26319537916d..811c45110dd1 100644
--- a/internal/service/scheduler/schedule.go
+++ b/internal/service/scheduler/schedule.go
@@ -151,7 +151,7 @@ func resourceSchedule() *schema.Resource {
 								Schema: map[string]*schema.Schema{
 									"arn": {
 										Type:             schema.TypeString,
-										Optional:         true,
+										Required:         true,
 										ValidateDiagFunc: validation.ToDiagFunc(verify.ValidARN),
 									},
 								},
diff --git a/website/docs/r/scheduler_schedule.html.markdown b/website/docs/r/scheduler_schedule.html.markdown
index a831ab2c4959..0d63c00ebdbc 100644
--- a/website/docs/r/scheduler_schedule.html.markdown
+++ b/website/docs/r/scheduler_schedule.html.markdown
@@ -107,7 +107,7 @@ The following arguments are optional:
 
 #### dead_letter_config Configuration Block
 
-* `arn` - (Optional) ARN of the SQS queue specified as the destination for the dead-letter queue.
+* `arn` - (Required) ARN of the SQS queue specified as the destination for the dead-letter queue.
 
 #### ecs_parameters Configuration Block