Lyon is a pillar of the San Francisco LGBTQ community and a civil rights pioneer.
She co-founded the Daughters of Bilitis, the nation's first lesbian organization and was a journalist who began her career as a reporter in 1946.
Lyon and her wife, Del Martin, were the first to be married by Gavin Newsom during the so-called Winter of Love in Feb. 2004 at San Francisco City Hall after 54 years together.
"We lost a giant today," Sen. Wiener said. "Phyllis Lyon fought for LGBTQ equality when it was neither safe nor popular to do so. Phyllis and her wife Del Martin played a crucial role winning the rights and dignity our community now enjoys. We owe Phyllis immense gratitude for her work. Rest in power."