diff --git a/base/allocator/partition_allocator/address_space_randomization.h b/base/allocator/partition_allocator/address_space_randomization.h
index 43033d728050a..4287cd5644823 100644
--- a/base/allocator/partition_allocator/address_space_randomization.h
+++ b/base/allocator/partition_allocator/address_space_randomization.h
@@ -125,10 +125,10 @@ AslrMask(uintptr_t bits) {

       // ARM64 on Linux has 39-bit user space. Use 38 bits since ASLROffset()
       // could cause a carry.
-      constexpr ALWAYS_INLINE uintptr_t ASLRMask() {
+      PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t ASLRMask() {
         return AslrMask(38);
       }
-      constexpr ALWAYS_INLINE uintptr_t ASLROffset() {
+      PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE uintptr_t ASLROffset() {
         return AslrAddress(0x1000000000ULL);
       }

diff --git a/base/allocator/partition_allocator/page_allocator.cc b/base/allocator/partition_allocator/page_allocator.cc
index 524e107418501..d2cbf866212e7 100644
--- a/base/allocator/partition_allocator/page_allocator.cc
+++ b/base/allocator/partition_allocator/page_allocator.cc
@@ -28,6 +28,22 @@
 #error Platform not supported.
 #endif

+#if BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+
+#include <unistd.h>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wglobal-constructors"
+
+const PageCharacteristics kPage = []() {
+  int size = getpagesize();
+  return PageCharacteristics{size, __builtin_ctz(size)};
+}();
+
+#pragma GCC diagnostic pop
+
+#endif
+
 namespace partition_alloc {

 namespace {
diff --git a/base/allocator/partition_allocator/page_allocator_constants.h b/base/allocator/partition_allocator/page_allocator_constants.h
index 12515b9a02865..bec35d191e738 100644
--- a/base/allocator/partition_allocator/page_allocator_constants.h
+++ b/base/allocator/partition_allocator/page_allocator_constants.h
@@ -24,6 +24,18 @@
 // elimination.
 #define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const))

+#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+
+// Linux ARM64 can have different page sizes depending on the kernel.
+#define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const))
+
+struct PageCharacteristics {
+  int size;
+  int shift;
+};
+
+extern const PageCharacteristics kPage;
+
 #else

 // When defined, page size constants are fixed at compile time. When not
@@ -50,6 +62,8 @@ PageAllocationGranularityShift() {
   return 14;  // 16kB
 #elif BUILDFLAG(IS_APPLE) && defined(ARCH_CPU_64_BITS)
   return vm_page_shift;
+#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+  return kPage.shift;
 #else
   return 12;  // 4kB
 #endif
diff --git a/base/allocator/partition_allocator/partition_alloc_constants.h b/base/allocator/partition_allocator/partition_alloc_constants.h
index e0c871d6f60fe..e0d5702ac71ea 100644
--- a/base/allocator/partition_allocator/partition_alloc_constants.h
+++ b/base/allocator/partition_allocator/partition_alloc_constants.h
@@ -84,6 +84,11 @@ PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t
 PartitionPageShift() {
   return vm_page_shift + 2;
 }
+#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t
+PartitionPageShift() {
+  return kPage.shift + 2;
+}
 #else
 PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR ALWAYS_INLINE size_t
 PartitionPageShift() {
diff --git a/base/allocator/partition_allocator/partition_page.h b/base/allocator/partition_allocator/partition_page.h
index 9419fa4c44f2d..de5907d6a324c 100644
--- a/base/allocator/partition_allocator/partition_page.h
+++ b/base/allocator/partition_allocator/partition_page.h
@@ -134,6 +134,9 @@ struct __attribute__((packed)) SlotSpanMetadata {
   // PartitionPageSize() is 4 times the OS page size.
   static constexpr size_t kMaxSlotsPerSlotSpan =
       4 * (1 << 14) / kSmallestBucket;
+#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+  static constexpr size_t kMaxSlotsPerSlotSpan =
+      4 * (1 << 14) / kSmallestBucket;
 #else
   // A slot span can "span" multiple PartitionPages, but then its slot size is
   // larger, so it doesn't have as many slots.
diff --git a/base/allocator/partition_allocator/partition_root.cc b/base/allocator/partition_allocator/partition_root.cc
index 70d7d63ff4c65..c31356e0f0421 100644
--- a/base/allocator/partition_allocator/partition_root.cc
+++ b/base/allocator/partition_allocator/partition_root.cc
@@ -309,7 +309,7 @@ static size_t PartitionPurgeSlotSpan(
   constexpr size_t kMaxSlotCount =
       (PartitionPageSize() * kMaxPartitionPagesPerRegularSlotSpan) /
       SystemPageSize();
-#elif BUILDFLAG(IS_APPLE)
+#elif BUILDFLAG(IS_APPLE) || (BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64))
   // It's better for slot_usage to be stack-allocated and fixed-size, which
   // demands that its size be constexpr. On OS_APPLE, PartitionPageSize() is
   // always SystemPageSize() << 2, so regardless of what the run time page size