Highlighting figures compiled by the party through government data, the Labour leader said Conservative cuts to clinics means those in need "won't be able to easily access the vital drug", Truvada.
Before a decision is made to roll-out the drug nationally, NHS England is currently running a three-year assessment of Truvada PrEP to assess its cost effectiveness and over 10,000 individuals are involved in a trial.
Addressing Pink News' annual awards in event in Westminster, Mr Corbyn said frequent testing and the use of PrEP has had a "major contribution" in reducing the number of people contracting HIV.
"The LGBT community fought hard to get HIV awareness on the agenda but Conservative cuts to sexual health services mean that those in need won't be able to easily access the vital drug," he said.
Labour claims that in the coming year, 95 councils will cut sexual health service budgets by £17.6m, despite suggestions many clinics are already at "tipping point".
Theresa May, who attended the Pink News event last year but was in Brussels on Wednesday evening for an EU council summit, addressed attendees via a pre-recorded video message and expressed her continuing support for a public consultation over reforms to the 2004 Gender Recognition Act (GRA).
The prime minister's comments came before the 16-week consultation into reforms close for submissions on Friday. Ultimately, the aim is to determine the best course of action for making it easier for trans individuals to change their gender legally by less intrusive and bureaucratic means.
Echoing Ms May's remarks, Mr Corbyn, said his party supports reforms to the 14-year-old legislation, adding: "Trans people must be able to live full, healthy, and happy lives - being the person they want to be. Labour will stand up for their right to do so."
Appearing at the event in Westminster on Wednesday evening, former Labour prime minister Tony Blair also hailed the changing cultural landscape for gay rights in Britain as he handed a lifetime achievement award to the founders of the prominent LGBT+ charity, Stonewall.
Vince Cable, the Liberal Democrat leader, used his address to hit out at the application process for LGBT+ asylum seekers, describing it as "humiliating" and "Dickensian".
He told attendees: They are forced to answer explicit questions about sexual activities and screenshots of their conversations on dating sites. Such humiliation would never be expected – or tolerated – if it was dished out to straight people.
"We know that decision-making in the Home Office is extremely poor, with over a third of all asylum applications that are refused overturned on appeal
"We must eradicate the Home Office's culture of disbelief. That means officials must never be allowed to state that an applicant is not LGBT+ so as to justify refusal."