Los Che have won just one of their five games since the league returned from its coronavirus-enforced stoppage, and they have been victorious twice in their past 13 outings in all competitions.
Celades, took over from from Marcelino in September, leaves the club eighth in LaLiga, eight points adrift of the Champions League places.
The 44-year-old led Valencia to the last-16 stage of the Champions League where the team was beaten 8-4 on aggregate by Atalanta.
Valencia currently sit eighth in the LaLiga standings, eight points away from a Champions League place.
The sacking was confirmed in an official club statement: "Valencia CF have communicated to Albert Celades his removal from his position as first team coach, with immediate effect.
"The club wish to thank him publicly for his work and dedication during his time at the club - a period in which we achieved qualification for the knockout stages of the Champions League and important victories at grounds where we had previously not won.
"The club also value his help and contribution since he took over as coach of the first team in a moment of difficulty, and wish him every success in his future endeavours.
"From Tuesday, Voro González will take charge of the first team on a provisional basis through to the end of the present season."
Valencia face Athletic Club in a LaLiga game at Mestalla in their next outing.