"Tomer has been brilliant for the club since we signed him in 2015... He was a key player for us in our promotion-winning season, and this season he has made the step up to the Premier League," manager Chris Hughton told the club's website.
"We have all been absolutely delighted with his contribution, and this new contract is hard earned and well deserved."
Hemed, 30, served a three-match suspension for violent conduct last month and returned to action in Brighton's 1-0 win at Swansea City earlier this month.
Brighton host 14th-placed Stoke City in the league on Monday.
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(Reporting by Aditi Prakash in Bengaluru)
