diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 8b2b9ea..b23b749 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -78,6 +78,7 @@
  * SHA1      1                  0x0035-0x0035 0x0073-0x0073
  * SHA256    1                  0x0037-0x0037 0x0074-0x0074
  * SHA512    1                  0x0039-0x0039 0x0075-0x0075
+ * SHA-3    1 0x0076-0x0076
  * CHACHA20  3                  0x0051-0x0055
  * POLY1305  3                  0x0057-0x005B
  * CHACHAPOLY 2 0x0054-0x0056
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 2d32f67..35a4a0c 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -328,6 +328,7 @@
 //#define MBEDTLS_SHA1_ALT
 //#define MBEDTLS_SHA256_ALT
 //#define MBEDTLS_SHA512_ALT
+//#define MBEDTLS_SHA3_ALT
 
 /*
  * When replacing the elliptic curve module, pleace consider, that it is
@@ -2864,6 +2865,17 @@
 #define MBEDTLS_SHA512_C
 
 /**
+ * \def MBEDTLS_SHA3_C
+ *
+ * Enable the SHA3 cryptographic hash algorithm.
+ *
+ * Module:  library/sha3.c
+ *
+ * This module adds support for SHA3.
+ */
+#define MBEDTLS_SHA3_C
+
+/**
  * \def MBEDTLS_SHA512_USE_A64_CRYPTO_IF_PRESENT
  *
  * Enable acceleration of the SHA-512 cryptographic hash algorithm with the
diff --git a/include/mbedtls/sha3.h b/include/mbedtls/sha3.h
new file mode 100644
index 0000000..adecdc7
--- /dev/null
+++ b/include/mbedtls/sha3.h
@@ -0,0 +1,198 @@
+/**
+ * \file sha3.h
+ *
+ * \brief This file contains SHA3 definitions and functions.
+ *
+ * The Secure Hash Algorithms cryptographic
+ * hash functions are defined in <em>FIPS 202: SHA-3 Standard:
+ * Permutation-Based Hash and Extendable-Output Functions </em>.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef MBEDTLS_SHA3_H
+#define MBEDTLS_SHA3_H
+#include "mbedtls/private_access.h"
+
+#include "mbedtls/build_info.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** SHA3 input data was malformed. */
+#define MBEDTLS_ERR_SHA3_BAD_INPUT_DATA                 -0x0076
+
+/**
+ * SHA-3 family id.
+ *
+ * It identifies the family (SHA3-256, SHA3-512, etc.)
+ */
+
+typedef enum
+{
+    MBEDTLS_SHA3_NONE = 0, /*!< Operation not defined. */
+    MBEDTLS_SHA3_224, /*!< SHA3-224 */
+    MBEDTLS_SHA3_256, /*!< SHA3-256 */
+    MBEDTLS_SHA3_384, /*!< SHA3-384 */
+    MBEDTLS_SHA3_512, /*!< SHA3-512 */
+} mbedtls_sha3_id;
+
+#if !defined(MBEDTLS_SHA3_ALT)
+// Regular implementation
+//
+
+struct mbedtls_sha3_context;
+typedef struct mbedtls_sha3_family_functions
+{
+    mbedtls_sha3_id id;
+
+    uint16_t r;
+    uint16_t olen;
+    uint8_t xor_byte;
+}
+mbedtls_sha3_family_functions;
+
+/**
+ * \brief          The SHA-3 context structure.
+ *
+ *                 The structure is used SHA-3 checksum calculations.
+ */
+typedef struct mbedtls_sha3_context {
+    uint64_t state[25];
+    uint8_t index;
+    uint8_t id;
+
+    uint16_t r;
+    uint16_t olen;
+    uint8_t xor_byte;
+    uint16_t max_block_size;
+}
+mbedtls_sha3_context;
+
+#else  /* MBEDTLS_SHA3_ALT */
+#include "sha3_alt.h"
+#endif /* MBEDTLS_SHA3_ALT */
+
+/**
+ * \brief          This function initializes a SHA-3 context.
+ *
+ * \param ctx      The SHA-3 context to initialize. This must not be \c NULL.
+ */
+void mbedtls_sha3_init( mbedtls_sha3_context *ctx );
+
+/**
+ * \brief          This function clears a SHA-3 context.
+ *
+ * \param ctx      The SHA-3 context to clear. This may be \c NULL, in which
+ *                 case this function returns immediately. If it is not \c NULL,
+ *                 it must point to an initialized SHA-3 context.
+ */
+void mbedtls_sha3_free( mbedtls_sha3_context *ctx );
+
+/**
+ * \brief          This function clones the state of a SHA-3 context.
+ *
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The context to clone. This must be initialized.
+ */
+void mbedtls_sha3_clone( mbedtls_sha3_context *dst,
+                           const mbedtls_sha3_context *src );
+
+/**
+ * \brief          This function starts a SHA-3 checksum
+ *                 calculation.
+ *
+ * \param ctx      The context to use. This must be initialized.
+ * \param id       The id of the SHA-3 family.
+ *
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
+ */
+int mbedtls_sha3_starts( mbedtls_sha3_context *ctx, mbedtls_sha3_id id );
+
+/**
+ * \brief          This function feeds an input buffer into an ongoing
+ *                 SHA-3 checksum calculation.
+ *
+ * \param ctx      The SHA-3 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ *
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
+ */
+int mbedtls_sha3_update( mbedtls_sha3_context *ctx,
+                           const uint8_t *input,
+                           size_t ilen );
+
+/**
+ * \brief          This function finishes the SHA-3 operation, and writes
+ *                 the result to the output buffer.
+ *
+ * \param ctx      The SHA-3 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param output   The SHA-3 checksum result.
+ *                 This must be a writable buffer of length \c olen bytes.
+ * \param olen     Defines a variable output length (in bytes). \c output must be
+ *                 \c olen bytes length. For SHA-3 224, SHA-3 256, SHA-3 384 and
+ *                 SHA-3 512 must equal to 28, 32, 48 and 64, respectively.
+ *
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
+ */
+int mbedtls_sha3_finish( mbedtls_sha3_context *ctx,
+                           uint8_t *output, size_t olen );
+
+/**
+ * \brief          This function calculates the SHA-3
+ *                 checksum of a buffer.
+ *
+ *                 The function allocates the context, performs the
+ *                 calculation, and frees the context.
+ *
+ *                 The SHA-3 result is calculated as
+ *                 output = SHA-3(id, input buffer, d).
+ *
+ * \param id       The id of the SHA-3 family.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-3 checksum result.
+ *                 This must be a writable buffer of length \c olen bytes.
+ * \param olen     Determines the length (in bytes) of the output. \c output
+ *                 must be \c olen bytes length.
+ *
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
+ */
+int mbedtls_sha3( mbedtls_sha3_id id, const uint8_t *input,
+                    size_t ilen,
+                    uint8_t *output,
+                    size_t olen );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* mbedtls_sha3.h */
+