TeamCity supports the following authentication schemes:

Please refer to Configuring Authentication Settings for specific authentication scheme configuration.

The TeamCity server supports basic HTTP authentication allowing to access certain web server pages and perform actions from various scripts. Please refer to the Accessing Server by HTTP page for details.

See also:

Administrator's Guide: Accessing Server by HTTP | LDAP Integration | Configuring Authentication Settings
UI Reference: Server Configuration
Extending TeamCity: Custom Authentication Module