The history of the fight for LGBTI rights in Australia highlights the positive role the Left has played. Starting with the some of the early socialist literature and tracing the role of the Communist Party since its formation in 1920, the chapter looks at the early liberationist approach, then the impact of Stalinism. Overturning views of a conservative 1950s, it looks at the rise of the 1960s to 1970s protest movements and the critical role of the organised Left. Then came the explosive impact of Mardi Gras in 1978, followed by the close of this phase of radicalism begun by Gay Liberation. LGBTI struggle did not disappear, nor did the Left’s involvement. From the HIV-AIDS crisis and ACT-UP, through to the campus upsurge in QUEER activism during the anti-capitalist movement. The 2004 amendment to the Marriage Act to exclude LGBTI people sparked a mass civil rights fight, the Equal Love campaign, now on the verge of victory. Gay Liberation drew much of its theory from Women’s Liberation, initially based on a Marxist analysis of oppression. This chapter will address the following issues in Australia: how the analysis was debated out in the movement, what resonance did it have, how it affected the movement’s strategy and tactics, and whether a Marxist analysis has left a legacy for today’s struggles.