diff --git a/src/commands/commandUtils.ml b/src/commands/commandUtils.ml
index b8f2804de62..d8f39685635 100644
--- a/src/commands/commandUtils.ml
+++ b/src/commands/commandUtils.ml
@@ -1378,7 +1378,6 @@ let make_options
       |> min Sys_utils.nbr_procs;
     opt_suppress_types = FlowConfig.suppress_types flowconfig;
     opt_max_literal_length = FlowConfig.max_literal_length flowconfig;
-    opt_as_const = Base.Option.value ~default:true (FlowConfig.enable_as_const flowconfig);
     opt_component_syntax = FlowConfig.component_syntax flowconfig;
     opt_react_rules = FlowConfig.react_rules flowconfig;
     opt_hook_compatibility = FlowConfig.hook_compatibility flowconfig;
diff --git a/src/commands/config/flowConfig.ml b/src/commands/config/flowConfig.ml
index b547a34b12c..3b255031e9b 100644
--- a/src/commands/config/flowConfig.ml
+++ b/src/commands/config/flowConfig.ml
@@ -59,7 +59,6 @@ module Opts = struct
     react_rules: Options.react_rules list;
     dev_only_refinement_info_as_errors: bool;
     emoji: bool option;
-    enable_as_const: bool option;
     enable_const_params: bool option;
     enums: bool;
     estimate_recheck_time: bool option;
@@ -196,7 +195,6 @@ module Opts = struct
       react_rules = [];
       dev_only_refinement_info_as_errors = false;
       emoji = None;
-      enable_as_const = None;
       enable_const_params = None;
       enums = false;
       estimate_recheck_time = None;
@@ -414,20 +412,6 @@ module Opts = struct
       ]
       (fun opts v -> Ok { opts with casting_syntax = Some v })
 
-  let const_assertion_parser =
-    boolean (fun opts v ->
-        match opts.casting_syntax with
-        | None
-        | Some Options.CastingSyntax.As
-        | Some Options.CastingSyntax.Both ->
-          Ok { opts with enable_as_const = Some v }
-        | Some Options.CastingSyntax.Colon ->
-          Error
-            ("Setting \"as_const\" to true requires that \"casting_syntax\" "
-            ^ "is set to \"as\" or \"both\"."
-            )
-    )
-
   let channel_mode_parser ~enabled =
     enum
       [("pipe", `pipe); ("socket", `socket)]
@@ -998,7 +982,6 @@ module Opts = struct
       ("enums", boolean (fun opts v -> Ok { opts with enums = v }));
       ("estimate_recheck_time", estimate_recheck_time_parser);
       ("exact_by_default", boolean (fun opts v -> Ok { opts with exact_by_default = Some v }));
-      ("as_const", const_assertion_parser);
       ( "experimental.const_params",
         boolean (fun opts v -> Ok { opts with enable_const_params = Some v })
       );
@@ -1707,8 +1690,6 @@ let dev_only_refinement_info_as_errors c = c.options.Opts.dev_only_refinement_in
 
 let emoji c = c.options.Opts.emoji
 
-let enable_as_const c = c.options.Opts.enable_as_const
-
 let enable_const_params c = c.options.Opts.enable_const_params
 
 let enums c = c.options.Opts.enums
diff --git a/src/commands/config/flowConfig.mli b/src/commands/config/flowConfig.mli
index 65504576bf5..7d885e5503a 100644
--- a/src/commands/config/flowConfig.mli
+++ b/src/commands/config/flowConfig.mli
@@ -96,8 +96,6 @@ val dev_only_refinement_info_as_errors : config -> bool
 
 val emoji : config -> bool option
 
-val enable_as_const : config -> bool option
-
 val enable_const_params : config -> bool option
 
 val enums : config -> bool
diff --git a/src/common/options.ml b/src/common/options.ml
index 9e37440908b..c01a2f1a4c1 100644
--- a/src/common/options.ml
+++ b/src/common/options.ml
@@ -73,7 +73,6 @@ end
 
 type t = {
   opt_all: bool;
-  opt_as_const: bool;
   opt_autoimports: bool;
   opt_autoimports_min_characters: int;
   opt_autoimports_ranked_by_usage: bool;
@@ -170,8 +169,6 @@ type t = {
 
 let all opts = opts.opt_all
 
-let as_const opts = opts.opt_as_const
-
 let autoimports opts = opts.opt_autoimports
 
 let autoimports_min_characters opts = opts.opt_autoimports_min_characters
diff --git a/src/flow_dot_js.ml b/src/flow_dot_js.ml
index 08af5594c32..95519f186b7 100644
--- a/src/flow_dot_js.ml
+++ b/src/flow_dot_js.ml
@@ -110,7 +110,6 @@ let stub_metadata ~root ~checked =
         [ValidateRefAccessDuringRender; DeepReadOnlyProps; DeepReadOnlyHookReturns; RulesOfHooks];
     react_rules_always = false;
     dev_only_refinement_info_as_errors = false;
-    enable_as_const = true;
     enable_const_params = false;
     enable_enums = true;
     enable_jest_integration = false;
diff --git a/src/services/code_action/__tests__/refactor_extract_utils_tests.ml b/src/services/code_action/__tests__/refactor_extract_utils_tests.ml
index 6cfca5af798..f75d4ff6c4c 100644
--- a/src/services/code_action/__tests__/refactor_extract_utils_tests.ml
+++ b/src/services/code_action/__tests__/refactor_extract_utils_tests.ml
@@ -43,7 +43,6 @@ let stub_metadata ~root ~checked =
     react_rules = [];
     react_rules_always = false;
     dev_only_refinement_info_as_errors = false;
-    enable_as_const = false;
     enable_const_params = false;
     enable_enums = true;
     enable_jest_integration = false;
diff --git a/src/typing/__tests__/type_hint_test.ml b/src/typing/__tests__/type_hint_test.ml
index e60e5c90428..d5e6283b27f 100644
--- a/src/typing/__tests__/type_hint_test.ml
+++ b/src/typing/__tests__/type_hint_test.ml
@@ -34,7 +34,6 @@ let metadata =
     react_rules = [];
     react_rules_always = false;
     dev_only_refinement_info_as_errors = false;
-    enable_as_const = false;
     enable_const_params = false;
     enable_enums = true;
     enable_jest_integration = false;
diff --git a/src/typing/__tests__/typed_ast_test.ml b/src/typing/__tests__/typed_ast_test.ml
index b3d18f91b64..e655de9a9cc 100644
--- a/src/typing/__tests__/typed_ast_test.ml
+++ b/src/typing/__tests__/typed_ast_test.ml
@@ -32,7 +32,6 @@ let metadata =
     react_rules = [];
     react_rules_always = false;
     dev_only_refinement_info_as_errors = false;
-    enable_as_const = false;
     enable_const_params = false;
     enable_enums = true;
     enable_jest_integration = false;
diff --git a/src/typing/context.ml b/src/typing/context.ml
index 03f7261e6b0..23eeb2df7f5 100644
--- a/src/typing/context.ml
+++ b/src/typing/context.ml
@@ -43,7 +43,6 @@ type metadata = {
   react_rules: Options.react_rules list;
   react_rules_always: bool;
   dev_only_refinement_info_as_errors: bool;
-  enable_as_const: bool;
   enable_const_params: bool;
   enable_enums: bool;
   enable_jest_integration: bool;
@@ -271,7 +270,6 @@ let metadata_of_options options =
     react_rules = Options.react_rules options;
     react_rules_always = false;
     dev_only_refinement_info_as_errors = Options.dev_only_refinement_info_as_errors options;
-    enable_as_const = Options.as_const options;
     enable_const_params = Options.enable_const_params options;
     enable_enums = Options.enums options;
     enable_jest_integration = Options.enable_jest_integration options;
@@ -485,8 +483,6 @@ let react_rule_enabled cx rule = List.mem rule cx.metadata.react_rules
 
 let dev_only_refinement_info_as_errors cx = cx.metadata.dev_only_refinement_info_as_errors
 
-let enable_as_const cx = cx.metadata.enable_as_const
-
 let enable_const_params cx =
   cx.metadata.enable_const_params || cx.metadata.strict || cx.metadata.strict_local
 
diff --git a/src/typing/context.mli b/src/typing/context.mli
index 921a6d5d0e9..04175e592f1 100644
--- a/src/typing/context.mli
+++ b/src/typing/context.mli
@@ -87,7 +87,6 @@ type metadata = {
   react_rules: Options.react_rules list;
   react_rules_always: bool;
   dev_only_refinement_info_as_errors: bool;
-  enable_as_const: bool;
   enable_const_params: bool;
   enable_enums: bool;
   enable_jest_integration: bool;
@@ -183,8 +182,6 @@ val react_rules_always : t -> bool
 
 val dev_only_refinement_info_as_errors : t -> bool
 
-val enable_as_const : t -> bool
-
 val enable_const_params : t -> bool
 
 val enable_enums : t -> bool
diff --git a/src/typing/errors/error_message.ml b/src/typing/errors/error_message.ml
index 881a5dcd3d6..99d7211787e 100644
--- a/src/typing/errors/error_message.ml
+++ b/src/typing/errors/error_message.ml
@@ -716,7 +716,6 @@ and ts_syntax_kind =
   | TSTypeParamExtends
   | TSReadonlyVariance
   | TSInOutVariance of [ `In | `Out | `InOut ]
-  | TSAsConst of Options.CastingSyntax.t
   | TSSatisfiesType of Options.CastingSyntax.t
   | TSReadonlyType of [ `Tuple | `Array ] option
 
@@ -2805,7 +2804,6 @@ let friendly_message_of_msg = function
     | TSInOutVariance `In -> Normal MessageTSVarianceIn
     | TSInOutVariance `Out -> Normal MessageTSVarianceOut
     | TSInOutVariance `InOut -> Normal MessageTSVarianceInOut
-    | TSAsConst enabled_casting_syntax -> Normal (MessageTSAsConst enabled_casting_syntax)
     | TSSatisfiesType enabled_casting_syntax ->
       Normal (MessageTSSatisfiesType enabled_casting_syntax)
     | TSReadonlyType (Some arg_kind) ->
diff --git a/src/typing/errors/flow_intermediate_error.ml b/src/typing/errors/flow_intermediate_error.ml
index c4d27ebca66..20942a194a1 100644
--- a/src/typing/errors/flow_intermediate_error.ml
+++ b/src/typing/errors/flow_intermediate_error.ml
@@ -3502,20 +3502,6 @@ let to_printable_error :
         text " inside object methods since these methods may be unbound and rebound.";
       ]
       @ suggestion
-    | MessageTSAsConst enabled_casting_syntax ->
-      let (example, _) = type_casting_examples enabled_casting_syntax in
-      [
-        code "as const";
-        text " syntax is not enabled by default. ";
-        text "Try adding a type annotation instead. ";
-        text "You can cast an expression to a type using the form ";
-        code example;
-        text ". ";
-        text "Alternatively, you can enable experimental support for ";
-        text "the feature by setting ";
-        code "as_const=true";
-        text " in your flow config.";
-      ]
     | MessageTSKeyofType ->
       [
         code "keyof";
diff --git a/src/typing/errors/flow_intermediate_error_types.ml b/src/typing/errors/flow_intermediate_error_types.ml
index bf60378c96d..07374d4af69 100644
--- a/src/typing/errors/flow_intermediate_error_types.ml
+++ b/src/typing/errors/flow_intermediate_error_types.ml
@@ -812,7 +812,6 @@ type 'loc message =
   | MessageThisInComponent of 'loc
   | MessageThisInExportedFunction
   | MessageThisSuperInObject of 'loc virtual_reason * This_finder.kind
-  | MessageTSAsConst of Options.CastingSyntax.t
   | MessageTSKeyofType
   | MessageTSNeverType
   | MessageTSParamExtends
diff --git a/src/typing/statement.ml b/src/typing/statement.ml
index 6cb13620b25..1a7840e4e23 100644
--- a/src/typing/statement.ml
+++ b/src/typing/statement.ml
@@ -2780,16 +2780,10 @@ module Make
           (Error_message.EInvalidTypeCastSyntax { loc; enabled_casting_syntax = casting_syntax });
         let t = AnyT.at (AnyError None) loc in
         ((loc, t), AsExpression (Tast_utils.error_mapper#as_expression cast)))
-    | AsConstExpression ({ AsConstExpression.expression = e; comments } as cast) ->
-      if Context.enable_as_const cx then (
-        check_const_assertion cx e;
-        let (((_, t), _) as e) = expression cx ~as_const:true e in
-        ((loc, t), AsConstExpression { AsConstExpression.expression = e; comments })
-      ) else
-        let kind = Error_message.TSAsConst (Context.casting_syntax cx) in
-        Flow_js_utils.add_output cx (Error_message.ETSSyntax { kind; loc });
-        let t = AnyT.at (AnyError None) loc in
-        ((loc, t), AsConstExpression (Tast_utils.error_mapper#as_const_expression cast))
+    | AsConstExpression { AsConstExpression.expression = e; comments } ->
+      check_const_assertion cx e;
+      let (((_, t), _) as e) = expression cx ~as_const:true e in
+      ((loc, t), AsConstExpression { AsConstExpression.expression = e; comments })
     | TSSatisfies cast ->
       Flow_js_utils.add_output
         cx