The SLK is a compact roadster manufactured by the Mercedes-Benz in two generations, R170 and R171, since 1997.

As one of the first modern retractable hardtop convertibles, the SLK followed the 1995 Mitsubishi 300GT Spyder and preceded other retractable hardtops such as the Peugeot 206cc, Lexus SC and the Mercedes-Benz SL-Class.

The designation SLK derives from the company's design mission to create a roadster that was at once sporty, light and short — in German: Sportlich, Leicht und Kurz.

The term SLK-Class is a Mercedes marketing term referring to the vehicle in all its engine configurations across both design generations. The R170-platform SLK 230 Kompressor was introduced in 1997 for model year 1998 to compete with the Porsche Boxster and BMW Z3. Setting it apart was its folding hardtop, though its additional weight detracting from the performance of the 185 hp 2.3 L supercharged I4 engine and automatic transmission. The SLK was on Car and Driver's Ten Best list for 1997.

A 5-speed manual transmission was added for 1999 along with the 215 hp 3.2 L V6 and 6-speed manual transmission in the 2001 SLK 320.

An AMG model was added in 2001, with a 354 hp (264 kW) supercharged version of the 3.2 L V6. This SLK 32 AMG was the best-performing SLK ever, and was a direct rival of the BMW M Roadster and Porsche Boxster S. It is only offered with automatic transmission. The SLK AMG engine is also hand built.

Not all Mercedes SLKs were built in Bremen, Germany, the SLK 320 being built in South Africa. The very first R170 Mercedes SLK was completed on January 29, 1997 and last on April 7, 2004.