Sigma Theta Psi (ΣΘΨ) is a multicultural, academic, and social sorority. The sorority was founded at San Jose State University (SJSU) in 1991. Sigma Theta Psi is known for their significant contribution to breast cancer awareness throughout sisters' local campuses and communities and even nationwide.

The Founding Mothers of Sigma Theta Psi created the sorority on November 13, 1991 at San Jose State University. Over time, the sorority expanded and now has 13 chapters.

Sigma Theta Psi's colors are purple, black, and gold. Its mascot is a black panther and its flower is an orchid. Each year, chapters organize multicultural, social, and academic events ranging from step shows to guest speakers to professional development events.

Since Sigma Theta Psi is also an academic sorority, members are required to maintain a minimum grade point average (GPA). Thus, each member's primary focus should be on their academic studies.

The sorority's national philanthropy is breast cancer awareness. Their current beneficiary is the American Cancer Society. Sigma Theta Psi's annual event to raise money for this organization and local organizations is their Double D Brunch. This event is a national luncheon hosted in both California and Nevada.