diff --git a/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
--- a/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
@@ -206,7 +206,7 @@
 
   auto Init =
       anyOf(initListExpr(anyOf(allOf(initCountIs(1), hasInit(0, InitBase)),
-                               initCountIs(0))),
+                               initCountIs(0), hasType(arrayType()))),
             InitBase);
 
   Finder->addMatcher(
@@ -267,20 +267,30 @@
   CharSourceRange InitRange =
       CharSourceRange::getCharRange(LParenEnd, Init->getRParenLoc());
 
-  bool ValueInit = isa<ImplicitValueInitExpr>(Init->getInit());
-  bool CanAssign = UseAssignment && (!ValueInit || !Init->getInit()->getType()->isEnumeralType());
+  const Expr *InitExpression = Init->getInit();
+  const QualType InitType = InitExpression->getType();
+
+  const bool ValueInit =
+      isa<ImplicitValueInitExpr>(InitExpression) && !isa<ArrayType>(InitType);
+  const bool CanAssign =
+      UseAssignment && (!ValueInit || !InitType->isEnumeralType());
+  const bool NeedsBraces = !CanAssign || isa<ArrayType>(InitType);
 
   auto Diag =
       diag(Field->getLocation(), "use default member initializer for %0")
-      << Field
-      << FixItHint::CreateInsertion(FieldEnd, CanAssign ? " = " : "{")
-      << FixItHint::CreateInsertionFromRange(FieldEnd, InitRange);
+      << Field;
+
+  if (CanAssign)
+    Diag << FixItHint::CreateInsertion(FieldEnd, " = ");
+  if (NeedsBraces)
+    Diag << FixItHint::CreateInsertion(FieldEnd, "{");
 
   if (CanAssign && ValueInit)
-    Diag << FixItHint::CreateInsertion(
-        FieldEnd, getValueOfValueInit(Init->getInit()->getType()));
+    Diag << FixItHint::CreateInsertion(FieldEnd, getValueOfValueInit(InitType));
+  else
+    Diag << FixItHint::CreateInsertionFromRange(FieldEnd, InitRange);
 
-  if (!CanAssign)
+  if (NeedsBraces)
     Diag << FixItHint::CreateInsertion(FieldEnd, "}");
 
   Diag << FixItHint::CreateRemoval(Init->getSourceRange());
@@ -294,8 +304,7 @@
     return;
 
   diag(Init->getSourceLocation(), "member initializer for %0 is redundant")
-      << Field
-      << FixItHint::CreateRemoval(Init->getSourceRange());
+      << Field << FixItHint::CreateRemoval(Init->getSourceRange());
 }
 
 } // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -325,6 +325,10 @@
   constructors toward hand written constructors so that they are skipped if more
   than one exists.
 
+- Fixed crash in :doc:`modernize-use-default-member-init
+  <clang-tidy/checks/modernize/use-default-member-init>` with array members which
+  are value initialized.
+
 - Fixed false positive in :doc:`modernize-use-equals-default
   <clang-tidy/checks/modernize/use-equals-default>` check for special member
   functions containing macros or preprocessor directives, and out-of-line special
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init-assignment.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init-assignment.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init-assignment.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init-assignment.cpp
@@ -190,3 +190,39 @@
 
 NegativeTemplate<int> nti;
 NegativeTemplate<double> ntd;
+
+namespace PR63285 {
+
+class ArrayValueInit {
+  ArrayValueInit() : m_array() {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayValueInit()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1] = {};
+};
+
+class ArrayBraceInit {
+  ArrayBraceInit() : m_array{} {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInit()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1] = {};
+};
+
+class ArrayBraceInitWithValue {
+  ArrayBraceInitWithValue() : m_array{3.14} {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInitWithValue()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1] = {3.14};
+};
+
+class ArrayBraceInitMultipleValues {
+  ArrayBraceInitMultipleValues() : m_array{1.0, 2.0, 3.0} {}
+  double m_array[3];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInitMultipleValues()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[3] = {1.0, 2.0, 3.0};
+};
+
+} // namespace PR63285
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-default-member-init.cpp
@@ -482,3 +482,39 @@
   // CHECK-FIXES:      {{^  }}EmptyBracedIntDefault()  {}
   // CHECK-FIXES-NEXT: {{^  }}int m_i{};
 };
+
+namespace PR63285 {
+
+class ArrayValueInit {
+  ArrayValueInit() : m_array() {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayValueInit()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1]{};
+};
+
+class ArrayBraceInit {
+  ArrayBraceInit() : m_array{} {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInit()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1]{};
+};
+
+class ArrayBraceInitWithValue {
+  ArrayBraceInitWithValue() : m_array{3.14} {}
+  double m_array[1];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInitWithValue()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[1]{3.14};
+};
+
+class ArrayBraceInitMultipleValues {
+  ArrayBraceInitMultipleValues() : m_array{1.0, 2.0, 3.0} {}
+  double m_array[3];
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use default member initializer for 'm_array' [modernize-use-default-member-init]
+  // CHECK-FIXES:      {{^  }}ArrayBraceInitMultipleValues()  {}
+  // CHECK-FIXES-NEXT: {{^  }}double m_array[3]{1.0, 2.0, 3.0};
+};
+
+} // namespace PR63285