Michael Callen, American singer-songwriter and AIDS activist (d. 1993)
Michael Callen (April 11, 1955 – December 27, 1993) was an American singer, songwriter, composer, author, and AIDS activist. Callen was diagnosed with AIDS in 1982 and became a pioneer of AIDS activism in New York City, working closely with his doctor, Dr. Joseph Sonnabend, and Richard Berkowitz. Together, they published articles and pamphlets to raise awareness about the correlation between risky sexual behaviors and AIDS.

As a major contributor to the foundation of AIDS activism, specifically activism from people with AIDS, Callen helped draft unprecedented documents such as How to Have Sex in an Epidemic: One Approach, and The Denver Principles. In addition to his written work, Callen was a leader and founder of activist organizations including The People with AIDS Coalition and the Community Research Initiative. As a musician, he was a member of the openly gay and politically active a cappella quintet The Flirtations and released his own solo album, Purple Heart in 1988. He consistently spoke out for AIDS activist and gay and lesbian organizations and made frequent speaking appearances. Callen remained a primary public figure in AIDS activism until he died at age 38 from AIDS-related complications of pulmonary Kaposi's sarcoma at Midway Hospital in Los Angeles, California.