Cissokho has been linked with a number of Premier League clubs during the course of the transfer window, including Everton, Newcastle United and Manchester United.
The 24-year-old has joined Los Che for a fee believed to be in the region of £6m.
Valencia sporting director Braulio Vazquez said that he was delighted with the capture.
He told the club's official website: "Aly is a player with vast international experience that belies his youth. He has played for the French national team and has participated in high-level games in competitions such as the Champions League.
"Cissokho is physically powerful, very strong defensively and someone who will increase the competitiveness of of the team, especially on the left side."
Valencia made a strong start to their La Liga campaign last weekend, securing a credible 1-1 draw away to reigning champions Real Madrid.