Walsh spent most of his childhood in Clonmel, County Tipperary. His twenties were spent mainly in the gay civil rights movement in Dublin, during which time he was one of the prime movers behind Dublin's LGBT community space, the Hirschfeld Centre.
Walsh was president of the National Lesbian and Gay Federation (NLGF) from 1984 to 1988, at a time when it was co-litigant with Senator David Norris in his constitutional action (Norris v. Attorney General). During this period Walsh worked as a staff reporter with Ireland's first commercial gay magazine, OUT, which folded in 1988. Walsh along with gay activist Catherine Glendon founded Gay Community News, an A3 newspaper which he also edited during its first two years. GCN is Ireland's longest running gay publication.
After ten years of activism, Walsh followed his boyfriend to London where he remained for a time, before returning to his native town and launching himself as a DJ and club promoter. Throughout the 1990s, Walsh played at well known club nights among them Horny Organ Tribe, Elevator, the fetish club GAG, Powderbubble, H.A.M., Cork's club Telefunkin and the HIV/AIDS fund-raising alternative beauty pageant Alternative Miss Ireland.
In 1997, he reorganised NLGF's archive holdings into what would later become the Irish Queer Archive (IQA). Drawing on materials from IQA's collection, Walsh curated both "Pride and Protest" at Belfast's Central Library (2005) and "Revolting Homosexuals" (Outhouse and GUBU, Dublin 2004). On the 16th June 2008, the Irish Queer Archive officially transferred its materials to the National Library of Ireland marking it as a significant and historical event.
Walsh retired in 2006 as a professional DJ and club promoter to concentrate on a number of research and writing projects.
- "About GCN". Gay Community News (Dublin). Archived from the original on 2007-07-09. Retrieved 2007-07-10.
- "The Team". Alternative Miss Ireland. Archived from the original on 2007-06-07. Retrieved 2007-07-10.
- "Irish Queer Archive". Retrieved 2007-07-10.
- Cashin, Declan (2008-06-21). "Queer Times". Irish independent. Retrieved 2009-09-29.