diff --git a/.changeset/stale-turtles-hang.md b/.changeset/stale-turtles-hang.md
new file mode 100644
index 000000000000..f3744b7e1663
--- /dev/null
+++ b/.changeset/stale-turtles-hang.md
@@ -0,0 +1,6 @@
+---
+"@solana/signers": patch
+"@solana/keys": patch
+---
+
+Allow creating keypairs and keys from ReadonlyUint8Array
diff --git a/packages/keys/src/__typetests__/key-pair-typetests.ts b/packages/keys/src/__typetests__/key-pair-typetests.ts
new file mode 100644
index 000000000000..367b1cdc166d
--- /dev/null
+++ b/packages/keys/src/__typetests__/key-pair-typetests.ts
@@ -0,0 +1,6 @@
+import { ReadonlyUint8Array } from '@solana/codecs-core';
+
+import { createKeyPairFromBytes } from '../key-pair';
+
+createKeyPairFromBytes(new Uint8Array()) satisfies Promise<CryptoKeyPair>;
+createKeyPairFromBytes(new Uint8Array() as ReadonlyUint8Array) satisfies Promise<CryptoKeyPair>;
diff --git a/packages/keys/src/__typetests__/private-key-typetests.ts b/packages/keys/src/__typetests__/private-key-typetests.ts
new file mode 100644
index 000000000000..8bf613733857
--- /dev/null
+++ b/packages/keys/src/__typetests__/private-key-typetests.ts
@@ -0,0 +1,6 @@
+import { ReadonlyUint8Array } from '@solana/codecs-core';
+
+import { createPrivateKeyFromBytes } from '../private-key';
+
+createPrivateKeyFromBytes(new Uint8Array()) satisfies Promise<CryptoKey>;
+createPrivateKeyFromBytes(new Uint8Array() as ReadonlyUint8Array) satisfies Promise<CryptoKey>;
diff --git a/packages/keys/src/__typetests__/coercions-typetests.ts b/packages/keys/src/__typetests__/signatures-typetests.ts
similarity index 100%
rename from packages/keys/src/__typetests__/coercions-typetests.ts
rename to packages/keys/src/__typetests__/signatures-typetests.ts
diff --git a/packages/keys/src/key-pair.ts b/packages/keys/src/key-pair.ts
index 32c3264e8510..3eb0736b5311 100644
--- a/packages/keys/src/key-pair.ts
+++ b/packages/keys/src/key-pair.ts
@@ -1,4 +1,5 @@
 import { assertKeyGenerationIsAvailable, assertPRNGIsAvailable } from '@solana/assertions';
+import { ReadonlyUint8Array } from '@solana/codecs-core';
 import {
     SOLANA_ERROR__KEYS__INVALID_KEY_PAIR_BYTE_LENGTH,
     SOLANA_ERROR__KEYS__PUBLIC_KEY_MUST_MATCH_PRIVATE_KEY,
@@ -18,7 +19,7 @@ export async function generateKeyPair(): Promise<CryptoKeyPair> {
     return keyPair as CryptoKeyPair;
 }
 
-export async function createKeyPairFromBytes(bytes: Uint8Array, extractable?: boolean): Promise<CryptoKeyPair> {
+export async function createKeyPairFromBytes(bytes: ReadonlyUint8Array, extractable?: boolean): Promise<CryptoKeyPair> {
     assertPRNGIsAvailable();
 
     if (bytes.byteLength !== 64) {
diff --git a/packages/keys/src/private-key.ts b/packages/keys/src/private-key.ts
index ec4e2f0c49e4..c623f46306f2 100644
--- a/packages/keys/src/private-key.ts
+++ b/packages/keys/src/private-key.ts
@@ -1,6 +1,7 @@
+import { ReadonlyUint8Array } from '@solana/codecs-core';
 import { SOLANA_ERROR__KEYS__INVALID_PRIVATE_KEY_BYTE_LENGTH, SolanaError } from '@solana/errors';
 
-function addPkcs8Header(bytes: Uint8Array): Uint8Array {
+function addPkcs8Header(bytes: ReadonlyUint8Array): ReadonlyUint8Array {
     // prettier-ignore
     return new Uint8Array([
         /**
@@ -37,7 +38,7 @@ function addPkcs8Header(bytes: Uint8Array): Uint8Array {
     ]);
 }
 
-export async function createPrivateKeyFromBytes(bytes: Uint8Array, extractable?: boolean): Promise<CryptoKey> {
+export async function createPrivateKeyFromBytes(bytes: ReadonlyUint8Array, extractable?: boolean): Promise<CryptoKey> {
     const actualLength = bytes.byteLength;
     if (actualLength !== 32) {
         throw new SolanaError(SOLANA_ERROR__KEYS__INVALID_PRIVATE_KEY_BYTE_LENGTH, {
diff --git a/packages/signers/src/keypair-signer.ts b/packages/signers/src/keypair-signer.ts
index 1cd7dc0661af..3b2a764e03c0 100644
--- a/packages/signers/src/keypair-signer.ts
+++ b/packages/signers/src/keypair-signer.ts
@@ -3,6 +3,7 @@ import { SOLANA_ERROR__SIGNER__EXPECTED_KEY_PAIR_SIGNER, SolanaError } from '@so
 import { createKeyPairFromBytes, generateKeyPair, signBytes } from '@solana/keys';
 import { partiallySignTransaction } from '@solana/transactions';
 
+import { ReadonlyUint8Array } from '../../codecs-core/dist/types';
 import { isMessagePartialSigner, MessagePartialSigner } from './message-partial-signer';
 import { isTransactionPartialSigner, TransactionPartialSigner } from './transaction-partial-signer';
 
@@ -66,6 +67,9 @@ export async function generateKeyPairSigner(): Promise<KeyPairSigner> {
 }
 
 /** Creates a signer capable of signing messages and transactions using the 64 bytes of a KeyPair. */
-export async function createKeyPairSignerFromBytes(bytes: Uint8Array, extractable?: boolean): Promise<KeyPairSigner> {
+export async function createKeyPairSignerFromBytes(
+    bytes: ReadonlyUint8Array,
+    extractable?: boolean,
+): Promise<KeyPairSigner> {
     return await createSignerFromKeyPair(await createKeyPairFromBytes(bytes, extractable));
 }