diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index de5c62295a5..7e68b94eb3e 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -772,6 +772,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Update `tags` and `threatintel.indicator.provider` fields in `threatintel.anomali` ingest pipeline {issue}24746[24746] {pull}27141[27141]
 - Move AWS module and filesets to GA. {pull}27428[27428]
 - update ecs.version to ECS 1.11.0. {pull}27107[27107]
+- Add base64 Encode functionality to httpjson input. {pull}27681[27681]
 
 *Heartbeat*
 
diff --git a/x-pack/filebeat/docs/inputs/input-httpjson.asciidoc b/x-pack/filebeat/docs/inputs/input-httpjson.asciidoc
index b9da841f721..1e928773da2 100644
--- a/x-pack/filebeat/docs/inputs/input-httpjson.asciidoc
+++ b/x-pack/filebeat/docs/inputs/input-httpjson.asciidoc
@@ -204,6 +204,8 @@ Some built-in helper functions are provided to work with the input state inside
 - `mul`: multiplies two integers.
 - `div`: does the integer division of two integer values.
 - `hmac`: calculates the hmac signature of a list of strings concatenated together. Supports sha1 or sha256. Example `[[hmac "sha256" "secret" "string1" "string2" (formatDate (now) "RFC1123")]]`
+- `base64Encode`: Joins and base64 encodes all supplied strings. Example `[[base64Encode "string1" "string2"]]`
+- `base64EncodeNoPad`: Joins and base64 encodes all supplied strings without padding. Example `[[base64EncodeNoPad "string1" "string2"]]`
 
 In addition to the provided functions, any of the native functions for https://golang.org/pkg/time/#Time[`time.Time`], https://golang.org/pkg/net/http/#Header[`http.Header`], and https://golang.org/pkg/net/url/#Values[`url.Values`] types can be used on the corresponding objects. Examples: `[[(now).Day]]`, `[[.last_response.header.Get "key"]]`
 
diff --git a/x-pack/filebeat/input/httpjson/internal/v2/value_tpl.go b/x-pack/filebeat/input/httpjson/internal/v2/value_tpl.go
index 0dd4f10e36a..b6c74590b9d 100644
--- a/x-pack/filebeat/input/httpjson/internal/v2/value_tpl.go
+++ b/x-pack/filebeat/input/httpjson/internal/v2/value_tpl.go
@@ -9,6 +9,7 @@ import (
 	"crypto/hmac"
 	"crypto/sha1"
 	"crypto/sha256"
+	"encoding/base64"
 	"encoding/hex"
 	"errors"
 	"hash"
@@ -54,6 +55,8 @@ func (t *valueTpl) Unpack(in string) error {
 			"mul":                 mul,
 			"div":                 div,
 			"hmac":                hmacString,
+			"base64Encode":        base64Encode,
+			"base64EncodeNoPad":   base64EncodeNoPad,
 		}).
 		Delims(leftDelim, rightDelim).
 		Parse(in)
@@ -243,6 +246,24 @@ func div(a, b int64) int64 {
 	return a / b
 }
 
+func base64Encode(values ...string) string {
+	data := strings.Join(values, "")
+	if data == "" {
+		return ""
+	}
+
+	return base64.StdEncoding.EncodeToString([]byte(data))
+}
+
+func base64EncodeNoPad(values ...string) string {
+	data := strings.Join(values, "")
+	if data == "" {
+		return ""
+	}
+
+	return base64.RawStdEncoding.EncodeToString([]byte(data))
+}
+
 func hmacString(hmacType string, hmacKey string, values ...string) string {
 	data := strings.Join(values[:], "")
 	if data == "" {
diff --git a/x-pack/filebeat/input/httpjson/internal/v2/value_tpl_test.go b/x-pack/filebeat/input/httpjson/internal/v2/value_tpl_test.go
index 2274a25614a..75f291b22be 100644
--- a/x-pack/filebeat/input/httpjson/internal/v2/value_tpl_test.go
+++ b/x-pack/filebeat/input/httpjson/internal/v2/value_tpl_test.go
@@ -276,6 +276,21 @@ func TestValueTpl(t *testing.T) {
 			expectedVal:   "",
 			expectedError: errEmptyTemplateResult.Error(),
 		},
+		{
+			name:        "func base64Encode 2 strings",
+			value:       `[[base64Encode "string1" "string2"]]`,
+			paramCtx:    emptyTransformContext(),
+			paramTr:     transformable{},
+			expectedVal: "c3RyaW5nMXN0cmluZzI=",
+		},
+		{
+			name:          "func base64Encode no value",
+			value:         `[[base64Encode ""]]`,
+			paramCtx:      emptyTransformContext(),
+			paramTr:       transformable{},
+			expectedVal:   "",
+			expectedError: errEmptyTemplateResult.Error(),
+		},
 	}
 
 	for _, tc := range cases {