Mark S. King (born December 23, 1960) is an American HIV/AIDS activist, blogger, writer, and actor. King tested positive for HIV in 1985 and became an HIV/AIDS activist soon after. In 2020, the Association of LGBTQ Journalists presented King with the Sarah Pettit Memorial Award for the LGBTQ Journalist of the Year. He is the creator of the video blog My Fabulous Disease, which won the 2020 GLAAD Media Award for Outstanding Blog. Out magazine named King to its 2020 Out100 list of LGBTQ+ influencers.