The 30-year-old had one year remaining on his current deal but his now likely to finish his career with the Dervishes.
He will receive EGP1.5 million per season to become the highest-earning player at the club.
"Hommos wasn't really appreciated during the past years so we felt we should reward him with such a deal," Ismaili chairman Nasr Aboul-Hassan told FilGoal.com.
The talented midfielder, a one-club man, has been one of the mainstays of Ismaili's squad since being promoted to the first team in 1997.
He won with the coastal club the Egyptian Cup in 2000 and the Premier League title in 2002.
Hommos was part of Egypt's squad that took part in the FIFA Confederations Cup in South Africa.
He scored the Pharaohs' winning goal in the historic 1-0 victory over world champions Italy.