Dr. Bob Deischer, Lambert House’s founder, was an out gay Pediatrician, and Director of the Center on Human Development and Disability at the University of Washington. He observed that LGBTQ+ young people in the clinics he oversaw were experiencing higher rates of negative health outcomes than their non-LGBTQ+ peers. He thought if they could just meet each other and have a way to make friends with other LGBTQ+ youth, their physical and mental health outcomes might improve.

With that vision, Lambert House was founded and received 501(c)3 status from the IRS in 1981 as the Association of Gay and Lesbian Youth Advocates (AGLYA). AGLYA was the first social service organization in the United States with a mission solely dedicated to LGBTQ+ youth to receive 501(c)3 status from the IRS.

In 1991, AGLYA seized an opportunity to lease an old Victorian house in Capitol Hill, Seattle's LGBTQ+ neighborhood. In 1993 AGLYA was renamed Lambert House after Gray Lambert, a local LGBTQ youth advocate who helped secure funding to find the organization a more stable home. Gray Lambert died of HIV/AIDS related complications in August of 1991.

Today, Lambert House has a national and international reputation as a leading organization in the Northwest for queer youth.