Uche's deal at El Madrigal had been due to expire at the end of the current campaign, but the former Getafe and Real Zaragoza forward has now committed his future to the Castellon club.
The 30-year-old has scored 14 league goals for Villarreal in each of the last two seasons.
His goalscoring form helped the team to promotion in 2013 and an impressive seventh-placed finish last term.
Uche has managed five goals in all competitions in the current campaign, while Villarreal are unbeaten in nine matches and sit sixth.
Marcelino's men face Deportivo La Coruna on Sunday.
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