Moses, 26, returned to Stamford Bridge from a loan spell at West Ham last season and has established himself as a regular under new Blues boss Antonio Conte.
"I feel very excited
I am delighted to be here for another few years now and to sign a new deal," Moses said on the club's official website.
"Now it is time to concentrate on the team and keep working hard to make sure we win games and try to win the Premier League this season."
Nigeria international Moses, who has agreed to extend his stay until 2021, believes Italian coach Conte has helped get the best out of his game.
"We are having a great season, I am enjoying my football and we have a good manager here that has given every single one of us confidence," Moses added.
"I just want to keep on enjoying it and working hard for the team."
Moses has started every Premier League match since October 1, when Conte switched to a 3-4-3 formation for the first time in the match against Hull.
Chelsea technical director Michael Emenalo is confident Moses has a big part to play at the west London club.
"Victor is enjoying an excellent season and, under Antonio's leadership, has proved to be an important member of the squad," Emenalo said.
"This new contract is testament to Victor's hard work and dedication to succeed at Chelsea and we believe he will be a big part of our future success."
Moses, who has helped Chelsea open up a 10-point lead in the Premier League, started his career at Crystal Palace and joined the Blues from Wigan in 2012.
The former winger spent spells at both Liverpool and Stoke before returning to London and then joining West Ham for the 2016/2017 campaign.
Source : PA
Source: PA