Index: clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.h
===================================================================
--- clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.h
+++ clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.h
@@ -84,6 +84,7 @@
   const bool IgnoreAllFloatingPointValues;
   const bool IgnoreBitFieldsWidths;
   const bool IgnorePowersOf2IntegerValues;
+  const bool IgnoreTypeAliases;
   const StringRef RawIgnoredIntegerValues;
   const StringRef RawIgnoredFloatingPointValues;
 
Index: clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.cpp
+++ clang-tools-extra/clang-tidy/readability/MagicNumbersCheck.cpp
@@ -14,6 +14,8 @@
 #include "MagicNumbersCheck.h"
 #include "../utils/OptionsUtils.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/AST/Type.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "llvm/ADT/STLExtras.h"
 #include <algorithm>
@@ -42,6 +44,18 @@
                       });
 }
 
+static bool isUsedToDefineATypeAlias(const MatchFinder::MatchResult &Result,
+                                     const DynTypedNode &Node) {
+
+  if (Node.get<TypeAliasDecl>() || Node.get<TypedefNameDecl>())
+    return true;
+
+  return llvm::any_of(Result.Context->getParents(Node),
+                      [&Result](const DynTypedNode &Parent) {
+                        return isUsedToDefineATypeAlias(Result, Parent);
+                      });
+}
+
 static bool isUsedToDefineABitField(const MatchFinder::MatchResult &Result,
                                     const DynTypedNode &Node) {
   const auto *AsFieldDecl = Node.get<FieldDecl>();
@@ -66,6 +80,7 @@
       IgnoreBitFieldsWidths(Options.get("IgnoreBitFieldsWidths", true)),
       IgnorePowersOf2IntegerValues(
           Options.get("IgnorePowersOf2IntegerValues", false)),
+      IgnoreTypeAliases(Options.get("IgnoreTypeAliases", false)),
       RawIgnoredIntegerValues(
           Options.get("IgnoredIntegerValues", DefaultIgnoredIntegerValues)),
       RawIgnoredFloatingPointValues(Options.get(
@@ -114,6 +129,7 @@
   Options.store(Opts, "IgnoreBitFieldsWidths", IgnoreBitFieldsWidths);
   Options.store(Opts, "IgnorePowersOf2IntegerValues",
                 IgnorePowersOf2IntegerValues);
+  Options.store(Opts, "IgnoreTypeAliases", IgnoreTypeAliases);
   Options.store(Opts, "IgnoredIntegerValues", RawIgnoredIntegerValues);
   Options.store(Opts, "IgnoredFloatingPointValues",
                 RawIgnoredFloatingPointValues);
@@ -137,10 +153,13 @@
                                    const Expr &ExprResult) const {
   return llvm::any_of(
       Result.Context->getParents(ExprResult),
-      [&Result](const DynTypedNode &Parent) {
+      [this, &Result](const DynTypedNode &Parent) {
         if (isUsedToInitializeAConstant(Result, Parent))
           return true;
 
+        if (IgnoreTypeAliases && isUsedToDefineATypeAlias(Result, Parent))
+          return true;
+
         // Ignore this instance, because this matches an
         // expanded class enumeration value.
         if (Parent.get<CStyleCastExpr>() &&
Index: clang-tools-extra/docs/ReleaseNotes.rst
===================================================================
--- clang-tools-extra/docs/ReleaseNotes.rst
+++ clang-tools-extra/docs/ReleaseNotes.rst
@@ -192,6 +192,11 @@
   <clang-tidy/checks/bugprone/too-small-loop-variable>` check. Basic support
   for bit-field and integer members as a loop variable or upper limit were added.
 
+- Improved :doc:`readability-magic-numbers 
+  <clang-tidy/checks/readability/magic-numbers>` check, now allows for
+  magic numbers in type aliases such as ``using`` and ``typedef`` declarations if
+  the new ``IgnoreTypeAliases`` option is set to true.
+
 Removed checks
 ^^^^^^^^^^^^^^
 
Index: clang-tools-extra/docs/clang-tidy/checks/readability/magic-numbers.rst
===================================================================
--- clang-tools-extra/docs/clang-tidy/checks/readability/magic-numbers.rst
+++ clang-tools-extra/docs/clang-tidy/checks/readability/magic-numbers.rst
@@ -24,6 +24,16 @@
 
 .. code-block:: c++
 
+   template<typename T, size_t N>
+   struct CustomType {
+      T arr[N];
+   };
+
+   struct OtherType {
+      CustomType<int, 30> container;
+   }
+   CustomType<int, 30> values;
+
    double circleArea = 3.1415926535 * radius * radius;
 
    double totalCharge = 1.08 * itemPrice;
@@ -40,6 +50,17 @@
 
 .. code-block:: c++
 
+   template<typename T, size_t N>
+   struct CustomType {
+      T arr[N];
+   };
+
+   using containerType = CustomType<int, 30>;
+   struct OtherType {
+      containerType container;
+   }
+   containerType values;
+
    double circleArea = M_PI * radius * radius;
 
    const double TAX_RATE = 0.08;  // or make it variable and read from a file
@@ -116,3 +137,8 @@
    Boolean value indicating whether to accept magic numbers as bit field widths
    without warning. This is useful for example for register definitions which
    are generated from hardware specifications. Default value is `true`.
+
+.. option:: IgnoreTypeAliases
+
+   Boolean value indicating whether to accept magic numbers in ``typedef`` or
+   ``using`` declarations. Default value is `false`.
Index: clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers-type-aliases.cpp
===================================================================
--- /dev/null
+++ clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers-type-aliases.cpp
@@ -0,0 +1,18 @@
+// RUN: %check_clang_tidy %s readability-magic-numbers %t \
+// RUN: -config='{CheckOptions: \
+// RUN:  [{key: readability-magic-numbers.IgnoreTypeAliases, value: true}]}' \
+// RUN: --
+
+template <typename T, int V>
+struct ValueBucket {
+  T value[V];
+};
+
+int BadGlobalInt = 5;
+// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: 5 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
+
+/**
+ * With the flag enabled these should produce no warning
+ */
+using NumberInTypeAlias = ValueBucket<int, 25>;
+typedef ValueBucket<char, 243> NumberInTypedef;
Index: clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers.cpp
@@ -3,7 +3,8 @@
 // RUN:  [{key: readability-magic-numbers.IgnoredIntegerValues, value: "0;1;2;10;100;"}, \
 // RUN:   {key: readability-magic-numbers.IgnoredFloatingPointValues, value: "3.14;2.71828;9.81;10000.0;101.0;0x1.2p3"}, \
 // RUN:   {key: readability-magic-numbers.IgnoreBitFieldsWidths, value: false}, \
-// RUN:   {key: readability-magic-numbers.IgnorePowersOf2IntegerValues, value: true}]}' \
+// RUN:   {key: readability-magic-numbers.IgnorePowersOf2IntegerValues, value: true}, \
+// RUN:   {key: readability-magic-numbers.IgnoreTypeAliases, value: false}]}' \
 // RUN: --
 
 template <typename T, int V>
@@ -96,6 +97,10 @@
    // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: 3 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
 };
 
+using NumberInTypeAlias = ValueBucket<int, 25>;
+// CHECK-MESSAGES: :[[@LINE-1]]:44: warning: 25 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
+typedef ValueBucket<char, 243> NumberInTypedef;
+// CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 243 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
 
 /*
  * Clean code