The 22-year-old joined the Toffees from Watford in the summer of 2018 for £40m and has been one of their must impressive players in a turbulent period.
Richarlison has scored 20 goals in 55 appearances for Everton in all competitions since his arrival, including four in 14 games this season.
Richarlison has become a full time Brazil international during his time at Everton.
He has won 19 caps for the Selecao, scoring six goals and was part of the side that won the Copa America on home soil in the summer.
"I intend to be here a long time. This was the club which gave me the opportunity to show my football," Richarlison said after inking his new deal.
"It was here I managed to get a place in the Brazil national team and it was here I have scored lots of goals in the Premier League."
"The club trusts me and I trust them," added the Brazilian.
"The supporters have a lot of affection for me and I try to give back all this affection as much as possible on the pitch.
"I go out and put my life on the line for them. I try to sweat blood and tears for this club. I intend to continue honouring the shirt and making the fans happy.
"And I hope they continue singing my name."
Everton lie 17th in the Premier League as they take in a difficult trip to leaders Liverpool on Wednesday.
