Adrian has agreed terms on a fresh deal at West Ham, manager Slaven Bilic confirmed on Friday.
The Spanish goalkeeper's contract was due to expire at the end of the season, but the Hammers have exercised their option to extend his stay for a further two years, ending speculation linking him with Crystal Palace and Everton.
Adrian joined the club from Real Betis in 2013 and has made 105 Premier League appearances since his arrival.
"With Adrian we had an option to extend his contract which we have done. He is our player and we're very happy," said Bilic ahead of Sunday's season-ending visit to Burnley.
Bilic also confirmed that defender Winston Reid would be out for around 10 weeks after undergoing surgery on a knee injury.
"He is good. He had an operation and will be out for 10 weeks, so he'll be ready for the start of next season," added the Croatian.
"It's important to finish with a win. Still we can improve our position. We will give everything to try to win the game.
"If we strengthen, settle down in the new stadium and learn from this season, we will improve next season."
The Hammers sit 12th, three points below ninth-placed West Brom.