The race is organised by the government together with Singapore GP.
Chase Carey, the chairman and CEO of Formula One, said the race was "a signature" of the World Championship calendar - and one of its most "thrilling events".
Officials said on Friday that the cost of hosting the race has been reduced to S$135 million ($100 million or 84 million euros).
In 2015, the average was 87,000 and the highest was 100,000 in 2008 when the first Singapore Grand Prix was hosted.
The new deal backed up Carey's words at the All That Matters industry conference in downtown Singapore this week. In next three to four years, we can take the sport to a place that is good for all our partners and really adds new level of excitement and dimension to the sport.More news: London police condemn Trump's 'loser terrorist' tweets following tube 'bucket bombing'
Therefore, after much speculation over the past few weeks, there will continue to be at least four power unit suppliers in Formula 1 over the next three years, with the ten teams now entered in the championship using either Honda, Renault, Mercedes or Ferrari engines.
Singapore has considerable appeal as a popular tourist destination, with about "40 to 50 percent of visitors (to the race) from overseas", said Lionel Yeo, the chief executive of Singapore's tourism board.
"We are looking forward to offering our continued support to make the next four years even more spectacular and exciting".
From next year, Singapore will be the sole stop that Formula One makes in Southeast Asia, as next month's Malaysian Grand Prix is to be the last. Aside from being a street race, the Singapore GP is also known for holding a strong line-up of concerts as well as other entertainment shows.