The 38-year-old joined Watford on a free transfer from Tottenham in May 2014.
The Brazilian goalkeeper has made 100 Premier League appearances for the Hornets.
Meanwhile, Gomes previous contract was set to expire at the end of this month.
But, Watford confirmed that the veteran keeper has penned a new one-year with them.
The announcement was disclosed through their official Twitter handle:
He's not going anywhere yet!
ONE. MORE. YEAR.@hdgomes 💛