Serhetabat (formerly Gushgy) (Turkmen: Guşgy; Russian: Кушка, Kushka) is a city in Tagtabazar District, Mary Province, Turkmenistan.

The name of the city is a Turkmen borrowing from Persian سرحدآباد, consisting of two words: سرحد (sarhadd) meaning "border" and آباد (ābād) meaning "inhabited place" (commonly used as a Persian suffix for naming places, such as Khorramabad, a city in Iran, and Ashgabat, the capital of Turkmenistan).

Gushgy is a Turkmenized form of the Persian word kushk (کوشک), a term referring to mountain forts.

In 1885 after taking the Panjdeh oasis Russian troops constructed a fort on the site of present-day Serhetabat and named it for the village of Kush in Afghanistan.

A local rail-line branching from Merv (now Mary) on the Central Asian Railway was inaugurated on 1 March 1901, causing some degree of international excitement.