diff --git a/changelogs/fragments/49688-docker_secret-config-base64-data.yml b/changelogs/fragments/49688-docker_secret-config-base64-data.yml
new file mode 100644
index 00000000000..4606c6ba2f4
--- /dev/null
+++ b/changelogs/fragments/49688-docker_secret-config-base64-data.yml
@@ -0,0 +1,3 @@
+minor_changes:
+- "docker_secret - ``data`` can now accept Base64-encoded data via the new ``data_is_b64`` option.
+   This allows to pass binary data or JSON data in unmodified form. (https://github.com/ansible/ansible/issues/35119)"
diff --git a/lib/ansible/modules/cloud/docker/docker_config.py b/lib/ansible/modules/cloud/docker/docker_config.py
index ac0a9fe2c3a..68a73d461ba 100644
--- a/lib/ansible/modules/cloud/docker/docker_config.py
+++ b/lib/ansible/modules/cloud/docker/docker_config.py
@@ -32,6 +32,14 @@ options:
       - The value of the config. Required when state is C(present).
     required: false
     type: str
+  data_is_b64:
+    description:
+      - If set to C(true), the data is assumed to be Base64 encoded and will be
+        decoded before being used.
+      - To use binary C(data), it is better to keep it Base64 encoded and let it
+        be decoded by this option.
+    default: false
+    type: bool
   labels:
     description:
       - "A map of key:value meta data, where both the I(key) and I(value) are expected to be a string."
@@ -80,7 +88,11 @@ EXAMPLES = '''
 - name: Create config foo (from a file on the control machine)
   docker_config:
     name: foo
-    data: "{{ lookup('file', '/path/to/config/file') }}"
+    # If the file is JSON or binary, Ansible might modify it (because
+    # it is first decoded and later re-encoded). Base64-encoding the
+    # file directly after reading it prevents this to happen.
+    data: "{{ lookup('file', '/path/to/config/file') | base64 }}"
+    data_is_b64: true
     state: present
 
 - name: Change the config data
@@ -144,12 +156,13 @@ config_id:
   sample: 'hzehrmyjigmcp2gb6nlhmjqcv'
 '''
 
+import base64
 import hashlib
 
 try:
     from docker.errors import APIError
 except ImportError:
-    # missing docker-py handled in ansible.module_utils.docker
+    # missing docker-py handled in ansible.module_utils.docker_common
     pass
 
 from ansible.module_utils.docker_common import AnsibleDockerClient, DockerBaseClass, compare_generic
@@ -170,13 +183,18 @@ class ConfigManager(DockerBaseClass):
         self.name = parameters.get('name')
         self.state = parameters.get('state')
         self.data = parameters.get('data')
+        if self.data is not None:
+            if parameters.get('data_is_b64'):
+                self.data = base64.b64decode(self.data)
+            else:
+                self.data = to_bytes(self.data)
         self.labels = parameters.get('labels')
         self.force = parameters.get('force')
         self.data_key = None
 
     def __call__(self):
         if self.state == 'present':
-            self.data_key = hashlib.sha224(to_bytes(self.data)).hexdigest()
+            self.data_key = hashlib.sha224(self.data).hexdigest()
             self.present()
         elif self.state == 'absent':
             self.absent()
@@ -252,6 +270,7 @@ def main():
         name=dict(type='str', required=True),
         state=dict(type='str', choices=['absent', 'present'], default='present'),
         data=dict(type='str'),
+        data_is_b64=dict(type='bool', default=False),
         labels=dict(type='dict'),
         force=dict(type='bool', default=False)
     )
diff --git a/lib/ansible/modules/cloud/docker/docker_secret.py b/lib/ansible/modules/cloud/docker/docker_secret.py
index a5aa00e5779..dcd924b049f 100644
--- a/lib/ansible/modules/cloud/docker/docker_secret.py
+++ b/lib/ansible/modules/cloud/docker/docker_secret.py
@@ -23,19 +23,30 @@ version_added: "2.4"
 description:
      - Create and remove Docker secrets in a Swarm environment. Similar to `docker secret create` and `docker secret rm`.
      - Adds to the metadata of new secrets 'ansible_key', an encrypted hash representation of the data, which is then used
-     - in future runs to test if a secret has changed.
-     - If 'ansible_key is not present, then a secret will not be updated unless the C(force) option is set.
+       in future runs to test if a secret has changed. If 'ansible_key is not present, then a secret will not be updated
+       unless the C(force) option is set.
      - Updates to secrets are performed by removing the secret and creating it again.
 options:
   data:
     description:
-      - String. The value of the secret. Required when state is C(present).
+      - The value of the secret. Required when state is C(present).
     required: false
+    type: str
+  data_is_b64:
+    description:
+      - If set to C(true), the data is assumed to be Base64 encoded and will be
+        decoded before being used.
+      - To use binary C(data), it is better to keep it Base64 encoded and let it
+        be decoded by this option.
+    default: false
+    type: bool
+    version_added: "2.8"
   labels:
     description:
       - "A map of key:value meta data, where both the I(key) and I(value) are expected to be a string."
       - If new meta data is provided, or existing meta data is modified, the secret will be updated by removing it and creating it again.
     required: false
+    type: dict
   force:
     description:
       - Use with state C(present) to always remove and recreate an existing secret.
@@ -46,6 +57,7 @@ options:
     description:
       - The name of the secret.
     required: true
+    type: str
   state:
     description:
       - Set to C(present), if the secret should exist, and C(absent), if it should not.
@@ -72,10 +84,14 @@ author:
 
 EXAMPLES = '''
 
-- name: Create secret foo
+- name: Create secret foo (from a file on the control machine)
   docker_secret:
     name: foo
-    data: Hello World!
+    # If the file is JSON or binary, Ansible might modify it (because
+    # it is first decoded and later re-encoded). Base64-encoding the
+    # file directly after reading it prevents this to happen.
+    data: "{{ lookup('file', '/path/to/secret/file') | base64 }}"
+    data_is_b64: true
     state: present
 
 - name: Change the secret data
@@ -134,11 +150,12 @@ RETURN = '''
 secret_id:
   description:
     - The ID assigned by Docker to the secret object.
-  returned: success
+  returned: success and C(state == "present")
   type: str
   sample: 'hzehrmyjigmcp2gb6nlhmjqcv'
 '''
 
+import base64
 import hashlib
 
 try:
@@ -165,13 +182,18 @@ class SecretManager(DockerBaseClass):
         self.name = parameters.get('name')
         self.state = parameters.get('state')
         self.data = parameters.get('data')
+        if self.data is not None:
+            if parameters.get('data_is_b64'):
+                self.data = base64.b64decode(self.data)
+            else:
+                self.data = to_bytes(self.data)
         self.labels = parameters.get('labels')
         self.force = parameters.get('force')
         self.data_key = None
 
     def __call__(self):
         if self.state == 'present':
-            self.data_key = hashlib.sha224(to_bytes(self.data)).hexdigest()
+            self.data_key = hashlib.sha224(self.data).hexdigest()
             self.present()
         elif self.state == 'absent':
             self.absent()
@@ -247,6 +269,7 @@ def main():
         name=dict(type='str', required=True),
         state=dict(type='str', choices=['absent', 'present'], default='present'),
         data=dict(type='str', no_log=True),
+        data_is_b64=dict(type='bool', default=False),
         labels=dict(type='dict'),
         force=dict(type='bool', default=False)
     )
diff --git a/test/integration/targets/docker_config/tasks/test_docker_config.yml b/test/integration/targets/docker_config/tasks/test_docker_config.yml
index 9956e5447be..d4482004930 100644
--- a/test/integration/targets/docker_config/tasks/test_docker_config.yml
+++ b/test/integration/targets/docker_config/tasks/test_docker_config.yml
@@ -70,6 +70,19 @@
       that:
          - not output.changed
 
+  - name: Create config again (base64)
+    docker_config:
+      name: db_password
+      data: b3BlbnNlc2FtZSE=
+      data_is_b64: true
+      state: present
+    register: output
+
+  - name: assert create config (base64) is idempotent
+    assert:
+      that:
+         - not output.changed
+
   - name: Update config
     docker_config:
       name: db_password
diff --git a/test/integration/targets/docker_secret/tasks/test_secrets.yml b/test/integration/targets/docker_secret/tasks/test_secrets.yml
index 03321ee1ddc..b99f059e052 100644
--- a/test/integration/targets/docker_secret/tasks/test_secrets.yml
+++ b/test/integration/targets/docker_secret/tasks/test_secrets.yml
@@ -70,6 +70,19 @@
       that:
          - not output.changed
 
+  - name: Create secret again (base64)
+    docker_secret:
+      name: db_password
+      data: b3BlbnNlc2FtZSE=
+      data_is_b64: true
+      state: present
+    register: output
+
+  - name: assert create secret (base64) is idempotent
+    assert:
+      that:
+         - not output.changed
+
   - name: Update secret
     docker_secret:
       name: db_password