A plumber wrench is a pipe wrench used to rotate pipes used in plumbing. The wrench is adjusted to different pipe diameters by rotating the key ring (silver in the picture). This tool can close with significant force (without caution it is possible to dent or break the pipe) and thus does not need to engage a nut. However, the tool can still be used on a pipe with a nut or other flat engagement points.

Being relatively large and unwieldy, this tool is only used when the ordinary wrenches are not suitable.

The plumber wrench was invented in the year 1888 by Swedish inventor Johan Petter Johansson, who also held an 1891 patent on an improved version of the adjustable spanner. This tool, which shares some principles with both the Stillson-pattern pipe wrench and the Ridgid-type pipe wrench, is nevertheless a decidedly different tool. Though not widely known in North America, it is commonly found in Europe, where it may be called a "pipe wrench" or a "Swedish wrench," one of its names in Italian, for example.