London will stage the 2016 European Championships in the first international event to be held at the Aquatics Centre since last year's Olympics.
The Stratford venue will also host the European Masters Championships, for swimmers over the age of 25.
The date has yet to be finalised but, given it is an Olympic year, the event will be held earlier than its usual date of July or August.
Boris Johnson, the Mayor of London, who is also chairman of the London Legacy Development Corporation, hailed the news, which comes 12 months after the successful staging of the Olympics at the east London venue.
"This is simply fantastic news for London and a glowing testimony for the Olympic Park's status as a world-beating destination for elite sport," Johnson said.
"The stunning Aquatics Centre, home to some of the most dramatic sporting moments during the Olympic and Paralympic Games, is a fitting setting for these flagship international championships."