The 26-year-old’s previous deal was set to expire in the summer, but the new deal will keep him at the club until 2014.
Martinez said: “We are delighted that Jordi is committing himself to our football club.
“He is our top goalscorer this season and his vision has provided us with a real playmaking role in the side.
“He has accumulated a fantastic experience in the Premier League and with potential offers waiting for him in the summer, it is a fantastic gesture towards the football club that he has chosen to commit to Wigan Athletic at this crucial moment of the season.”
Gomez joined Wigan from Espanyol in 2009.
He said: “I would like to thank everyone at the club for making me feel welcome.
“I feel I can keep improving here and now I want to keep focusing on my game and do all I can to finish the season strongly and keep our Premier League status.”
