diff --git a/changelog.md b/changelog.md
index c51d4e9c..360e5af8 100644
--- a/changelog.md
+++ b/changelog.md
@@ -6,6 +6,7 @@ Features
 * Let the `--dsn` argument accept literal DSNs as well as aliases.
 * Accept `--character-set` as an alias for `--charset` at the CLI.
 * Add SSL/TLS version to `status` output.
+* More liberally accept `on`/`off` values for `true`/`false`, and vice versa.
 
 
 Bug Fixes
diff --git a/mycli/config.py b/mycli/config.py
index a79b1021..17fe4541 100644
--- a/mycli/config.py
+++ b/mycli/config.py
@@ -305,6 +305,13 @@ def str_to_bool(s: str | bool) -> bool:
         raise ValueError(f'not a recognized boolean value: {s}')
 
 
+def str_to_on_off(s: str | bool) -> str:
+    bool_str = str(str_to_bool(s))
+    if bool_str == 'True':
+        return 'on'
+    return 'off'
+
+
 def strip_matching_quotes(s: str) -> str:
     """Remove matching, surrounding quotes from a string.
 
diff --git a/mycli/main.py b/mycli/main.py
index a3899fe0..f647462a 100755
--- a/mycli/main.py
+++ b/mycli/main.py
@@ -56,7 +56,15 @@
 from mycli.clitoolbar import create_toolbar_tokens_func
 from mycli.compat import WIN
 from mycli.completion_refresher import CompletionRefresher
-from mycli.config import get_mylogin_cnf_path, open_mylogin_cnf, read_config_files, str_to_bool, strip_matching_quotes, write_default_config
+from mycli.config import (
+    get_mylogin_cnf_path,
+    open_mylogin_cnf,
+    read_config_files,
+    str_to_bool,
+    str_to_on_off,
+    strip_matching_quotes,
+    write_default_config,
+)
 from mycli.key_bindings import mycli_bindings
 from mycli.lexer import MyCliLexer
 from mycli.packages import special
@@ -220,7 +228,9 @@ def __init__(
 
         # set ssl_mode if a valid option is provided in a config file, otherwise None
         ssl_mode = c["main"].get("ssl_mode", None) or c["connection"].get("default_ssl_mode", None)
-        if ssl_mode not in ("auto", "on", "off", None):
+        if ssl_mode is None:
+            self.ssl_mode = ssl_mode
+        elif ssl_mode.lower() not in ("auto", "on", "off", "1", "0", "true", "false"):
             self.echo(f"Invalid config option provided for ssl_mode ({ssl_mode}); ignoring.", err=True, fg="red")
             self.ssl_mode = None
         else:
@@ -1659,7 +1669,7 @@ def get_last_query(self) -> str | None:
     "--ssl-mode",
     "ssl_mode",
     help="Set desired SSL behavior. auto=preferred, on=required, off=off.",
-    type=click.Choice(["auto", "on", "off"]),
+    type=str,
 )
 @click.option("--ssl/--no-ssl", "ssl_enable", default=None, help="Enable SSL for connection (automatically enabled with other flags).")
 @click.option("--ssl-ca", help="CA file in PEM format.", type=click.Path(exists=True))
@@ -1995,6 +2005,14 @@ def get_password_from_file(password_file: str | None) -> str | None:
             ssl_enable = True
 
     ssl_mode = ssl_mode or mycli.ssl_mode  # cli option or config option
+    if ssl_mode:
+        ssl_mode = ssl_mode.lower()
+    if ssl_mode and ssl_mode != 'auto':
+        try:
+            ssl_mode = str_to_on_off(ssl_mode)
+        except ValueError:
+            click.secho('Unknown value for ssl_mode', err=True, fg='red')
+            sys.exit(1)
 
     # if there is a mismatch between the ssl_mode value and other sources of ssl config, show a warning
     # specifically using "is False" to not pickup the case where ssl_enable is None (not set by the user)
diff --git a/test/test_config.py b/test/test_config.py
index 5bb0ab4f..fda9bc4e 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -16,6 +16,7 @@
     read_and_decrypt_mylogin_cnf,
     read_config_file,
     str_to_bool,
+    str_to_on_off,
     strip_matching_quotes,
 )
 
@@ -149,6 +150,25 @@ def test_str_to_bool():
         str_to_bool(None)
 
 
+def test_str_to_on_off():
+    assert str_to_on_off(False) == 'off'
+    assert str_to_on_off(True) == 'on'
+    assert str_to_on_off("False") == 'off'
+    assert str_to_on_off("True") == 'on'
+    assert str_to_on_off("TRUE") == 'on'
+    assert str_to_on_off("1") == 'on'
+    assert str_to_on_off("0") == 'off'
+    assert str_to_on_off("on") == 'on'
+    assert str_to_on_off("off") == 'off'
+    assert str_to_on_off("off") == 'off'
+
+    with pytest.raises(ValueError):
+        str_to_on_off("foo")
+
+    with pytest.raises(TypeError):
+        str_to_on_off(None)
+
+
 def test_read_config_file_list_values_default():
     """Test that reading a config file uses list_values by default."""
 
diff --git a/test/test_main.py b/test/test_main.py
index 1415f598..1fbd3e51 100644
--- a/test/test_main.py
+++ b/test/test_main.py
@@ -154,6 +154,17 @@ def test_ssl_mode_on(executor, capsys):
     assert ssl_cipher
 
 
+@dbtest
+def test_ssl_mode_true(executor, capsys):
+    runner = CliRunner()
+    ssl_mode = 'true'
+    sql = 'select * from performance_schema.session_status where variable_name = "Ssl_cipher"'
+    result = runner.invoke(cli, args=CLI_ARGS + ['--csv', '--ssl-mode', ssl_mode], input=sql)
+    result_dict = next(csv.DictReader(result.stdout.split('\n')))
+    ssl_cipher = result_dict.get('VARIABLE_VALUE', None)
+    assert ssl_cipher
+
+
 @dbtest
 def test_ssl_mode_auto(executor, capsys):
     runner = CliRunner()
@@ -176,6 +187,17 @@ def test_ssl_mode_off(executor, capsys):
     assert not ssl_cipher
 
 
+@dbtest
+def test_ssl_mode_false(executor, capsys):
+    runner = CliRunner()
+    ssl_mode = 'False'
+    sql = 'select * from performance_schema.session_status where variable_name = "Ssl_cipher"'
+    result = runner.invoke(cli, args=CLI_ARGS + ['--csv', '--ssl-mode', ssl_mode], input=sql)
+    result_dict = next(csv.DictReader(result.stdout.split('\n')))
+    ssl_cipher = result_dict.get('VARIABLE_VALUE', None)
+    assert not ssl_cipher
+
+
 @dbtest
 def test_ssl_mode_overrides_ssl(executor, capsys):
     runner = CliRunner()