diff --git a/Cargo.toml b/Cargo.toml
index e3d17d8029d..e9203fbaa37 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -60,6 +60,7 @@ wasm-ext-websocket = ["wasm-ext", "libp2p-wasm-ext/websocket"]
 websocket = ["libp2p-websocket"]
 yamux = ["libp2p-yamux"]
 secp256k1 = ["libp2p-core/secp256k1"]
+serde = ["libp2p-core/serde", "libp2p-kad/serde", "libp2p-gossipsub/serde"]
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/core/CHANGELOG.md b/core/CHANGELOG.md
index 88094516c9d..e66d75019cd 100644
--- a/core/CHANGELOG.md
+++ b/core/CHANGELOG.md
@@ -11,10 +11,13 @@
 
 - Add `ConnectedPoint::is_relayed` (see [PR 2392]).
 
+- Implement `Serialize` and `Deserialize` for `PeerId` (see [PR 2408])
+
 [PR 2339]: https://github.com/libp2p/rust-libp2p/pull/2339
 [PR 2350]: https://github.com/libp2p/rust-libp2p/pull/2350
 [PR 2352]: https://github.com/libp2p/rust-libp2p/pull/2352
 [PR 2392]: https://github.com/libp2p/rust-libp2p/pull/2392
+[PR 2408]: https://github.com/libp2p/rust-libp2p/pull/2408
 
 # 0.30.1 [2021-11-16]
 
diff --git a/core/Cargo.toml b/core/Cargo.toml
index 60c348fe258..e4423de3fa0 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -37,6 +37,7 @@ thiserror = "1.0"
 unsigned-varint = "0.7"
 void = "1"
 zeroize = "1"
+_serde = { package = "serde", version = "1", optional = true, features = ["derive"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 ring = { version = "0.16.9", features = ["alloc", "std"], default-features = false }
@@ -48,6 +49,8 @@ criterion = "0.3"
 libp2p-mplex = { path = "../muxers/mplex" }
 libp2p-noise = { path = "../transports/noise" }
 libp2p-tcp = { path = "../transports/tcp" }
+serde_json = "1.0"
+rmp-serde = "0.15"
 multihash = { version = "0.14", default-features = false, features = ["arb"] }
 quickcheck = "0.9.0"
 rand07 = { package = "rand", version = "0.7" }
@@ -59,6 +62,7 @@ prost-build = "0.9"
 default = [ "secp256k1", "ecdsa" ]
 secp256k1 = [ "libsecp256k1" ]
 ecdsa = [ "p256" ]
+serde = ["multihash/serde-codec", "_serde"]
 
 [[bench]]
 name = "peer_id"
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 1a7d841e342..594fb6681dc 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -35,6 +35,9 @@
 //!   define how to upgrade each individual substream to use a protocol.
 //!   See the `upgrade` module.
 
+#[cfg(feature = "serde")]
+extern crate _serde as serde;
+
 mod keys_proto {
     include!(concat!(env!("OUT_DIR"), "/keys_proto.rs"));
 }
diff --git a/core/src/peer_id.rs b/core/src/peer_id.rs
index 6e3823e64ed..518adcabd6c 100644
--- a/core/src/peer_id.rs
+++ b/core/src/peer_id.rs
@@ -24,6 +24,9 @@ use rand::Rng;
 use std::{convert::TryFrom, fmt, str::FromStr};
 use thiserror::Error;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// Public keys with byte-lengths smaller than `MAX_INLINE_KEY_LENGTH` will be
 /// automatically used as the peer id using an identity multihash.
 const MAX_INLINE_KEY_LENGTH: usize = 42;
@@ -164,6 +167,60 @@ impl From<PeerId> for Vec<u8> {
     }
 }
 
+#[cfg(feature = "serde")]
+impl Serialize for PeerId {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: _serde::Serializer,
+    {
+        if serializer.is_human_readable() {
+            serializer.serialize_str(&self.to_base58())
+        } else {
+            serializer.serialize_bytes(&self.to_bytes()[..])
+        }
+    }
+}
+
+#[cfg(feature = "serde")]
+impl<'de> Deserialize<'de> for PeerId {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        use serde::de::*;
+
+        struct PeerIdVisitor;
+
+        impl<'de> Visitor<'de> for PeerIdVisitor {
+            type Value = PeerId;
+
+            fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                write!(f, "valid peer id")
+            }
+
+            fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                PeerId::from_bytes(v).map_err(|_| Error::invalid_value(Unexpected::Bytes(v), &self))
+            }
+
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                PeerId::from_str(v).map_err(|_| Error::invalid_value(Unexpected::Str(v), &self))
+            }
+        }
+
+        if deserializer.is_human_readable() {
+            deserializer.deserialize_str(PeerIdVisitor)
+        } else {
+            deserializer.deserialize_bytes(PeerIdVisitor)
+        }
+    }
+}
+
 #[derive(Debug, Error)]
 pub enum ParseError {
     #[error("base-58 decode error: {0}")]
diff --git a/core/tests/serde.rs b/core/tests/serde.rs
new file mode 100644
index 00000000000..3bb98d4a5b6
--- /dev/null
+++ b/core/tests/serde.rs
@@ -0,0 +1,52 @@
+#![cfg(feature = "serde")]
+
+use std::str::FromStr;
+
+use libp2p_core::PeerId;
+
+extern crate _serde as serde;
+
+#[test]
+pub fn serialize_peer_id_json() {
+    let peer_id = PeerId::from_str("12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC").unwrap();
+    let json = serde_json::to_string(&peer_id).unwrap();
+    assert_eq!(
+        json,
+        r#""12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC""#
+    )
+}
+
+#[test]
+pub fn serialize_peer_id_msgpack() {
+    let peer_id = PeerId::from_str("12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC").unwrap();
+    let buf = rmp_serde::to_vec(&peer_id).unwrap();
+    assert_eq!(
+        &buf[..],
+        &[
+            0xc4, 38, // msgpack buffer header
+            0x00, 0x24, 0x08, 0x01, 0x12, 0x20, 0xe7, 0x37, 0x0c, 0x66, 0xef, 0xec, 0x80, 0x00,
+            0xd5, 0x87, 0xfc, 0x41, 0x65, 0x92, 0x8e, 0xe0, 0x75, 0x5f, 0x94, 0x86, 0xcb, 0x5c,
+            0xf0, 0xf7, 0x80, 0xd8, 0xe0, 0x6c, 0x98, 0xce, 0x7d, 0xa9
+        ]
+    );
+}
+
+#[test]
+pub fn deserialize_peer_id_json() {
+    let peer_id = PeerId::from_str("12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC").unwrap();
+    let json = r#""12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC""#;
+    assert_eq!(peer_id, serde_json::from_str(json).unwrap())
+}
+
+#[test]
+pub fn deserialize_peer_id_msgpack() {
+    let peer_id = PeerId::from_str("12D3KooWRNw2pJC9748Fmq4WNV27HoSTcX3r37132FLkQMrbKAiC").unwrap();
+    let buf = &[
+        0xc4, 38, // msgpack buffer header
+        0x00, 0x24, 0x08, 0x01, 0x12, 0x20, 0xe7, 0x37, 0x0c, 0x66, 0xef, 0xec, 0x80, 0x00, 0xd5,
+        0x87, 0xfc, 0x41, 0x65, 0x92, 0x8e, 0xe0, 0x75, 0x5f, 0x94, 0x86, 0xcb, 0x5c, 0xf0, 0xf7,
+        0x80, 0xd8, 0xe0, 0x6c, 0x98, 0xce, 0x7d, 0xa9,
+    ];
+
+    assert_eq!(peer_id, rmp_serde::from_read(&mut &buf[..]).unwrap());
+}
diff --git a/protocols/gossipsub/CHANGELOG.md b/protocols/gossipsub/CHANGELOG.md
index 5e2910d13eb..07e9f2ade52 100644
--- a/protocols/gossipsub/CHANGELOG.md
+++ b/protocols/gossipsub/CHANGELOG.md
@@ -9,11 +9,14 @@
 - Improve bandwidth performance by tracking IWANTs and reducing duplicate sends
   (see [PR 2327]).
 
+- Implement `Serialize` and `Deserialize` for `MessageId` and `FastMessageId` (see [PR 2408])
+
 - Fix `GossipsubConfigBuilder::build()` requiring `&self` to live for `'static` (see [PR 2409])
 
 [PR 2346]: https://github.com/libp2p/rust-libp2p/pull/2346
 [PR 2339]: https://github.com/libp2p/rust-libp2p/pull/2339
 [PR 2327]: https://github.com/libp2p/rust-libp2p/pull/2327
+[PR 2408]: https://github.com/libp2p/rust-libp2p/pull/2408
 [PR 2409]: https://github.com/libp2p/rust-libp2p/pull/2409
 
 # 0.34.0 [2021-11-16]
diff --git a/protocols/gossipsub/Cargo.toml b/protocols/gossipsub/Cargo.toml
index d408ec15a41..2b3fef066ac 100644
--- a/protocols/gossipsub/Cargo.toml
+++ b/protocols/gossipsub/Cargo.toml
@@ -30,6 +30,7 @@ regex = "1.4.0"
 futures-timer = "3.0.2"
 pin-project = "1.0.8"
 instant = "0.1.11"
+serde = { version = "1", optional = true, features = ["derive"] }
 # Metrics dependencies
 open-metrics-client = "0.14.0"
 
diff --git a/protocols/gossipsub/src/types.rs b/protocols/gossipsub/src/types.rs
index f9c2ddaeb57..fe7663d6cba 100644
--- a/protocols/gossipsub/src/types.rs
+++ b/protocols/gossipsub/src/types.rs
@@ -27,6 +27,9 @@ use prost::Message;
 use std::fmt;
 use std::fmt::Debug;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(Debug)]
 /// Validation kinds from the application for received messages.
 pub enum MessageAcceptance {
@@ -42,6 +45,7 @@ pub enum MessageAcceptance {
 /// Macro for declaring message id types
 macro_rules! declare_message_id_type {
     ($name: ident, $name_string: expr) => {
+        #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
         #[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
         pub struct $name(pub Vec<u8>);
 
diff --git a/protocols/kad/CHANGELOG.md b/protocols/kad/CHANGELOG.md
index 9be1e2f1222..eb5ff7d1309 100644
--- a/protocols/kad/CHANGELOG.md
+++ b/protocols/kad/CHANGELOG.md
@@ -6,8 +6,11 @@
 
 - Derive `Clone` for `KademliaEvent` (see [PR 2411])
 
+- Derive `Serialize`, `Deserialize` for `store::record::Key` (see [PR 2408])
+
 [PR 2339]: https://github.com/libp2p/rust-libp2p/pull/2339
 [PR 2411]: https://github.com/libp2p/rust-libp2p/pull/2411
+[PR 2408]: https://github.com/libp2p/rust-libp2p/pull/2408
 
 # 0.33.0 [2021-11-16]
 
diff --git a/protocols/kad/Cargo.toml b/protocols/kad/Cargo.toml
index 9007180f3f4..d5da320f422 100644
--- a/protocols/kad/Cargo.toml
+++ b/protocols/kad/Cargo.toml
@@ -29,6 +29,7 @@ unsigned-varint = { version = "0.7", features = ["asynchronous_codec"] }
 void = "1.0"
 futures-timer = "3.0.2"
 instant = "0.1.11"
+_serde = { package = "serde", version = "1.0", optional = true, features = ["derive"] }
 thiserror = "1"
 
 [dev-dependencies]
@@ -40,3 +41,6 @@ quickcheck = "0.9.0"
 
 [build-dependencies]
 prost-build = "0.9"
+
+[features]
+serde = ["_serde", "bytes/serde"]
diff --git a/protocols/kad/src/lib.rs b/protocols/kad/src/lib.rs
index d8734ec0d80..ef4943b2fb9 100644
--- a/protocols/kad/src/lib.rs
+++ b/protocols/kad/src/lib.rs
@@ -24,6 +24,9 @@
 //       be useful later for record store
 #![allow(dead_code)]
 
+#[cfg(feature = "serde")]
+extern crate _serde as serde;
+
 pub mod handler;
 pub mod kbucket;
 pub mod protocol;
diff --git a/protocols/kad/src/record.rs b/protocols/kad/src/record.rs
index e8e05670c79..e321992e5c7 100644
--- a/protocols/kad/src/record.rs
+++ b/protocols/kad/src/record.rs
@@ -25,10 +25,14 @@ pub mod store;
 use bytes::Bytes;
 use instant::Instant;
 use libp2p_core::{multihash::Multihash, Multiaddr, PeerId};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 use std::borrow::Borrow;
 use std::hash::{Hash, Hasher};
 
 /// The (opaque) key of a record.
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "serde", serde(crate = "_serde"))]
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Key(Bytes);