Astor Theatre, St Kilda, Art Deco movie theater in St Kilda, Australia.

The Astor Theatre is a single-screen Art Deco cinema on Chapel Street in St Kilda, Melbourne, listed on the Victorian Heritage Register. It has a stalls section and a curved balcony, and the original stage curtain is still in place.

The site at 1-3 Chapel Street hosted the Diamond Picture Theatre from 1912, later renamed Theatre Rex and closed in 1917. Frank O'Collins bought the property in 1935 and had architect Ron Morton Taylor design the Astor in jazz moderne style; it opened on 3 April 1936 with 1,673 seats. Bought by Tanda Investments in 1969, it screened only Greek-language films before a brief closure in 1982; it reopened in 1983 under George Florence with a screening of King Kong.

The Astor regularly screens retrospectives and themed film seasons that draw an audience devoted to watching older films on a big screen. The auditorium's curved balcony and working curtain system remind visitors that going to the cinema was once a formal occasion.

The Astor stands at 1-3 Chapel Street in St Kilda, not on a corner with Dandenong Road. Trams run along Chapel Street and St Kilda station is within walking distance. The single auditorium holds 1,200 seats across stalls and balcony, and the building is entered from Chapel Street beneath the Astor blade sign.

The Astor is one of the few cinemas in the world that still regularly screens films in 70mm print, a format known for its large image size. On those nights, the difference from digital projection is clearly noticeable to anyone sitting in the auditorium.