Valdo scored eight times in his 63 appearances for the Andalucian side during his two-year stint at the club, and played a key role this season as they performed above expectations in finishing in sixth place in La Liga.
The Cape Verdea international's move was announced on Twitter by the president of Atlante, Jose Antonio Garcia. "Welcome to Cancun!" wrote Garcia on the social networking site, in a series of tweets aimed at welcoming Atlante's new signing.
Valdo is not the first addition to the Iron Colts squad this summer, with Ignacio Torres, Jorge Villalpando and Chilean forward Esteban Paredes all signing for the club in recent weeks.