The suspect was arrested in South Norwood, London on 7 September on suspicion of two counts of GBH.
He remains in police custody at this time.
The stabbings, which took place at approximately 10:15pm on 13 August, are being treated as homophobic by the Metropolitan Police.
Two men, aged in their 20s and 30s, were standing outside the LGBTQ+ venue when a man approached them and attacked them with a knife before running away.
They were both taken to hospital for treatment and were discharged not long after the incident.
Detective Superintendent Vanessa Britton said: “This arrest marks a significant development in our investigation. The two victims have been informed and continue to be supported by our officers, including our dedicated LGBT+ Community Liaison Officer.
“I know the concern and distress this horrific incident has caused among the LGBT+ community and I want to reassure them – and Londoners as a whole – that a team of officers is working diligently to investigate.
”Pc Hayley Jones, the LGBT+ community liaison officer for the Metropolitan Police in Lambeth and Southwark, said: “We understand some people from the LGBT+ community may not have the confidence to speak to police.
“My role was introduced to provide a dedicated LGBT+ point of contact to support the community and advise on investigations where homophobia and transphobia is a motive.
“You can contact me directly for advice and support, or to assist this investigation.”
Anyone with information is asked to contact police on 101 or tweet @MetCC and quote CAD 7198/13Aug.
You can also provide information anonymously to the independent charity Crimestoppers on 0800 555 111.
You can view all of the available images of the suspect below.