The 24-year-old left-back joined the Spanish club on a four-year contract after spending the last three seasons in Ligue 1.
"This is a big step forward in my career," said Cissokho at his official unveiling. "I have arrived at a historic club and I can't wait to train with the team.
"Although football is a business, it is also a passion. That is why it was not difficult to take a cut in salary.
"In France, any player would love to come to Valencia."
Cissokho is the replacement for Jordi Alba at Mestalla, after the Spain international joined Barcelona earlier this summer.