The 35-year-old, who began his Grand Prix career in 2002, confirmed his long-expected departure during a news conference ahead of this weekend's Italian Grand Prix at Monza.
"I'm more nervous now than for all my race starts," said Massa, who missed out on the championship to Britain's Lewis Hamilton by one point in 2008 at the final race of the season in his native Brazil.
"After 27 years of my racing career, since I started karting and with 15 years in F1, this will be my last season in F1.
Massa started his career with Sauber before moving to Ferrari in 2006 and then Williams.
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He is in his third year with Williams, having joined the team in 2014, and will mark his 250th Grand Prix start at his final race in Abu Dhabi this year.
"Maybe you will see me again at the wheel of a race car, but at the moment the only certainty I have is that I will have a lot of time to decide on what I do in the future," the Brazilian added.
"Ten years on from that day, and in the same paddock, I decided to announce my decision," he said.