YPlan, which was launched in London in 2012 and is available for iOS and Android powered devices, will become the official "going out partner" of the London venue formerly known as The Millennium Dome.
The app lets users browse and book tickets for gigs, food tasting events, theatre shows and exhibitions at art galleries.
The deal between The O2 and YPlan is initially for three years and will be extended across other AEG-operated venues. The agreement was negotiated by AEG's sponsorship arm, AEG Global Partnerships.
Rebecca Kane, The O2’s general manager, said: "When you see an event you want to go on the night or up to a fortnight in advance, YPlan lets you book in just two taps.
"It’s as quick and simple as that. We want to make sure our customers can access tickets in as many ways as possible in addition to our AXS.com ticketing site, and the YPlan app is perfect for this."
Rytis Vitkauskas, YPlan’s chief executive and co-founder, said: "Partnerships like this are what YPlan is all about.
"We are always looking for ways to bring the best and most varied events to our customers and working with The O2 is a great way to increase the range of events showcased on the app.
"From tennis tournaments to top international music acts, The O2 has it all and we look forward to continuing this ongoing partnership."
The news comes in the wake of comments made by The O2 head of sponsorship Nuala Donnelly, who recently told Marketing that O2 had already built up strong relationships with promoters, and that it wanted to win over the music industry.