The Schleicher ASK 23 is a single-seat Club Class sailplane that was built by the German manufacturer Alexander Schleicher GmbH & Co.
The ASK 23 was the last glider to be designed by Rudolf Kaiser. It is an early-solo sailplane with docile handling, and was a successor to the Schleicher Ka 8 and ASK 18. It is also the single-seat counterpart of the two-seat Schleicher ASK 21 with a similar cockpit layout. It uses glass-fibre reinforced plastic and 'honeycomb' as its main construction materials. It has no flaps, a nose wheel and a fixed main-wheel with a tail-skid or optional tail-wheel.
First flown in October 1983, the initial version allowed for heavy pilots, with a maximum cockpit weight of 140kg (310lb), reduced to 120kg (270lb) in the later ASK23B version. 51 gliders of the original version were built, and 102 of the 'B' version.