Rahlstedt (German pronunciationⓘ) is a quarter (Stadtteil) in the Wandsbek borough (Bezirk) of the Free and Hanseatic city of Hamburg in northern Germany.

Rahlstedt was located on the eastern edge of the city of Hamburg, belonged to the Duchy of Holstein under the Danish crown and fell with it to Prussia in 1864.

It borders Hamburg's quarters of Volksdorf, Farmsen-Berne, Tonndorf and Jenfeld; and with the district of Stormarn, in Schleswig-Holstein.

The stream Wandse, originating near the municipality Siek (district Stormarn), and its confluents Rahlau, Stellau and Stellmoorer Quellfluss, run through Rahlstedt.

The most significant features, remains from the ice age, are located within the nature reserves Stellmoorer Tunneltal and Höltigbaum.