The Ruger SP101 is a series of double-action revolvers produced by the American company Sturm, Ruger & Co.

The SP101 is a small frame and all-steel-construction carry revolver, with a five-shot (.38 Special, .357 Magnum, and 9×19mm Parabellum); six-shot (.327 Federal Magnum, and .32 H&R Magnum); or eight-shot (.22 LR) cylinder.

The Ruger SP101 was introduced in 1989 as the smaller-frame counterpart to the GP100.

Together, these revolvers replaced Sturm, Ruger & Co's long-standing staple in the American firearms market, the Ruger Security-Six series revolvers.

A 9 mm version was available until its discontinuation around 1998 but was later re-released in early 2018.