The Brazilian driver Felipe Massa will replace Venezuelan Pastor Maldonado at Williams next season after signing a multi-year contract with the Formula One team.
Finland's Valtteri Bottas will remain as the former champions' other driver.
The 32-year-old has raced for Ferrari since 2006 with 11 grands prix wins during that period.
He missed out on the world championship by a single point in 2008 to Britain's Lewis Hamilton.
He follows in the footsteps of the late triple champion Ayrton Senna, Nelson Piquet, Rubens Barrichello and Bruno Senna as Brazilians to have driven for Williams.
Ferrari have already announced that 2007 world champion Kimi Raikkonen, who is out of contract with Lotus at the end of the season, will replace the Brazilian at the Italian team.
Maldonado brought substantial backing from Venezuelan oil company PDVSA to Williams when he arrived in 2011 but has become frustrated with the former champions, who have scored just one point this season.
