The ZSSK Class 350 (prior to 1988: ČSD Class ES 499.0) is an electric locomotive of the Železničná spoločnosť Slovensko (Slovak Railway Company) and previously of the Československé státní dráhy (Czechoslovak State Railways).

Introduced in 1974, they became the first dual-system locomotives in Czechoslovakia, and have been used to haul express trains on the Bratislava - Prague railway corridor since then.

They are nicknamed "Gorilla" among railfans due to this locomotive being featured in 1989 on a postage stamp of Guinea-Bissau.