CLAS LogoThe Celt Login Authentication System (CLAS) allows users to login to a variety of online services at University of St. Thomas (UST) with a single username (your Celt Login ID) and password for all CLAS enabled systems.

All UST students, faculty, and staff are provided with a Celt Login ID. Exactly when your Celt Login ID is created depends on your relationship with UST:

  • Undergraduate Students: After an Application for Admission is submitted and processed
  • Graduate Students: After acceptance and matriculation
  • Faculty & Staff: At start of employment

Activating Your Account

Before you can use your Celt Login ID you’ll need to activate it. The activation process will ask for some personal information to help identify you, including your UST ID number. Your ID number can be found on your UST ID Card or in your Admission packet. If you don’t know or can’t find your ID number, you may contact one of the following for help:

Once activated, your Celt Login ID and password can be used to access systems that display the Celt Login Authentication System (CLAS) logo. A few UST Systems that use CLAS include:

  • E-Mail
  • myStThom
  • Blackboard
  • Quarantine
  • Library Resource Access

Whether you’ve forgotten your password, locked yourself out, or allowed your password to expire, most password problems can be resolved through the CLAS password reset process. You’ll need your UST ID number and the answers to the security questions that you set when you activated your account to successfully reset your password.

Having Problems?

The CLAS FAQ can help with some common issues. If you can’t find a solution there, contact the IT Helpdesk by phone at 713-525-6900 or by e-mail at Be sure to include your student ID number.