diff --git a/Cargo.lock b/Cargo.lock
index c53f517..14fe937 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -115,6 +115,12 @@ dependencies = [
  "match-lookup",
 ]
 
+[[package]]
+name = "base45"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3103f6d6af63726e86b026ac66769fc578ea38aba33f409e5855a4def97a564"
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -479,6 +485,7 @@ version = "0.9.2"
 dependencies = [
  "base-x",
  "base256emoji",
+ "base45",
  "criterion",
  "data-encoding",
  "data-encoding-macro",
diff --git a/Cargo.toml b/Cargo.toml
index 131513a..47cda72 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,6 +19,7 @@ base-x = { version = "0.2.7", default-features = false }
 base256emoji = "1.0.2"
 data-encoding = { version = "2.3.1", default-features = false, features = ["alloc"] }
 data-encoding-macro = "0.1.9"
+base45 = "3.1.0"
 
 [dev-dependencies]
 criterion = "0.7"
diff --git a/cli/main.rs b/cli/main.rs
index 529b6d0..ec11468 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -84,6 +84,7 @@ impl fmt::Display for StrBase {
             Base::Base32Z => "base32z",
             Base::Base36Lower => "base36lower",
             Base::Base36Upper => "base36upper",
+            Base::Base45 => "base45",
             Base::Base58Flickr => "base58flickr",
             Base::Base58Btc => "base58btc",
             Base::Base64 => "base64",
@@ -118,6 +119,7 @@ impl FromStr for StrBase {
             "base32z" => Ok(Base::Base32Z),
             "base36lower" => Ok(Base::Base36Lower),
             "base36upper" => Ok(Base::Base36Upper),
+            "base45" => Ok(Base::Base45),
             "base58flickr" => Ok(Base::Base58Flickr),
             "base58btc" => Ok(Base::Base58Btc),
             "base64" => Ok(Base::Base64),
diff --git a/src/base.rs b/src/base.rs
index 40b55ab..470fc65 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -82,6 +82,8 @@ build_base_enum! {
     'k' => Base36Lower,
     /// Base36, [0-9A-Z] no padding (alphabet: 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ).
     'K' => Base36Upper,
+    /// Base45, rfc9285 (alphabet: 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:).
+    'R' => Base45,
     /// Base58 flicker (alphabet: 123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ).
     'Z' => Base58Flickr,
     /// Base58 bitcoin (alphabet: 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz).
diff --git a/src/error.rs b/src/error.rs
index 5fb14a6..790296c 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -41,3 +41,9 @@ impl From<data_encoding::DecodeError> for Error {
         Self::InvalidBaseString
     }
 }
+
+impl From<base45::DecodeError> for Error {
+    fn from(_: base45::DecodeError) -> Self {
+        Self::InvalidBaseString
+    }
+}
diff --git a/src/impls.rs b/src/impls.rs
index fbc915a..a8d255e 100644
--- a/src/impls.rs
+++ b/src/impls.rs
@@ -158,3 +158,17 @@ impl BaseCodec for Base36Upper {
         Ok(base_x::decode(encoding::BASE36_UPPER, &uppercased)?)
     }
 }
+
+/// Base45, rfc9285 (alphabet: 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:).
+pub(crate) struct Base45;
+
+impl BaseCodec for Base45 {
+    fn encode<I: AsRef<[u8]>>(input: I) -> String {
+        base45::encode(input.as_ref())
+    }
+
+    fn decode<I: AsRef<str>>(input: I) -> Result<Vec<u8>> {
+        let uppercased = input.as_ref().to_ascii_uppercase();
+        Ok(base45::decode(&uppercased)?)
+    }
+}
diff --git a/tests/lib.rs b/tests/lib.rs
index e0a7264..b222be0 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -58,6 +58,7 @@ fn test_basic() {
         (Base32Z, "hxf1zgedpcfzg1ebb"),
         (Base36Lower, "k2lcpzo5yikidynfl"),
         (Base36Upper, "K2LCPZO5YIKIDYNFL"),
+        (Base45, "RRFF.OEB$D5/DZ24"),
         (Base58Flickr, "Z7Pznk19XTTzBtx"),
         (Base58Btc, "z7paNL19xttacUY"),
         (Base64, "meWVzIG1hbmkgIQ"),
@@ -90,6 +91,7 @@ fn preserves_leading_zero() {
         (Base32Z, "hybhskh3ypiosh4jyrr"),
         (Base36Lower, "k02lcpzo5yikidynfl"),
         (Base36Upper, "K02LCPZO5YIKIDYNFL"),
+        (Base45, "RV206$CL44CEC2DDX0"),
         (Base58Flickr, "Z17Pznk19XTTzBtx"),
         (Base58Btc, "z17paNL19xttacUY"),
         (Base64, "mAHllcyBtYW5pICE"),
@@ -122,6 +124,7 @@ fn preserves_two_leading_zeroes() {
         (Base32Z, "hyyy813murbssn5ujryoo"),
         (Base36Lower, "k002lcpzo5yikidynfl"),
         (Base36Upper, "K002LCPZO5YIKIDYNFL"),
+        (Base45, "R000RFF.OEB$D5/DZ24"),
         (Base58Flickr, "Z117Pznk19XTTzBtx"),
         (Base58Btc, "z117paNL19xttacUY"),
         (Base64, "mAAB5ZXMgbWFuaSAh"),
@@ -149,6 +152,7 @@ fn case_insensitivity() {
         (Base32HexPadUpper, "Td1imor3f41RMUSJCCG======"),
         (Base36Lower, "kfUvrsIvVnfRbjWaJo"),
         (Base36Upper, "KfUVrSIVVnFRbJWAJo"),
+        (Base45, "R+8d vd82ek4f.kea2"),
     ];
     for (base, output) in test_cases {
         assert_eq!(decode(output).unwrap(), (base, input.to_vec()));