diff --git a/src/main/scala/org/camunda/feel/impl/builtin/StringBuiltinFunctions.scala b/src/main/scala/org/camunda/feel/impl/builtin/StringBuiltinFunctions.scala
index 23f573c2b..fa0b56eed 100644
--- a/src/main/scala/org/camunda/feel/impl/builtin/StringBuiltinFunctions.scala
+++ b/src/main/scala/org/camunda/feel/impl/builtin/StringBuiltinFunctions.scala
@@ -19,7 +19,8 @@ package org.camunda.feel.impl.builtin
 import com.fasterxml.uuid.{EthernetAddress, Generators}
 import org.camunda.feel.impl.builtin.BuiltinFunction.builtinFunction
 import org.camunda.feel.syntaxtree.{ValBoolean, ValError, ValList, ValNumber, ValString}
-
+import java.util.Base64
+import java.nio.charset.StandardCharsets
 import java.util.regex.Pattern
 import scala.util.Try
 
@@ -42,7 +43,8 @@ object StringBuiltinFunctions {
     "split"            -> List(splitFunction),
     "extract"          -> List(extractFunction),
     "trim"             -> List(trimFunction),
-    "uuid"             -> List(uuidFunction)
+    "uuid"             -> List(uuidFunction),
+    "to base64"        -> List(toBase64Function)
   )
 
   private def substringFunction = builtinFunction(
@@ -274,4 +276,14 @@ object StringBuiltinFunctions {
         ValString(generator.generate.toString())
       }
     )
+
+  private def toBase64Function =
+    builtinFunction(
+      params = List("value"),
+      invoke = { case List(ValString(value)) =>
+        val bytes = value.getBytes(StandardCharsets.UTF_8)
+        ValString(Base64.getEncoder.encodeToString(bytes))
+      }
+    )
+
 }
diff --git a/src/test/scala/org/camunda/feel/impl/builtin/BuiltinStringFunctionsTest.scala b/src/test/scala/org/camunda/feel/impl/builtin/BuiltinStringFunctionsTest.scala
index b73763f74..de7eac8f0 100644
--- a/src/test/scala/org/camunda/feel/impl/builtin/BuiltinStringFunctionsTest.scala
+++ b/src/test/scala/org/camunda/feel/impl/builtin/BuiltinStringFunctionsTest.scala
@@ -173,4 +173,11 @@ class BuiltinStringFunctionsTest extends AnyFlatSpec with Matchers with FeelInte
 
     eval(" string length(uuid()) ") should be(ValNumber(36))
   }
+
+  "A to base64() function" should "return a string encoded as base64" in {
+
+    eval(""" to base64("FEEL") """) should be(ValString("RkVFTA=="))
+
+    eval(""" to base64(value: "Camunda") """) should be(ValString("Q2FtdW5kYQ=="))
+  }
 }