The 3rd Swiss Regiment Reding was a unit of Swiss soldiers in the Spanish Army and one of several Swiss regiments serving the Spanish Crown in the 18th century. The regiment was founded by a royal proclamation of Philip V in 1742 and recruited from the Canton of Schwyz in central Switzerland.
It was the third Swiss regiment in service at the time (out of about a dozen or so Swiss Regiments historically) and was the second raising of a regiment under Theodor von Reding. It is therefore either referred to as the 2nd Regiment Reding or the 3rd Swiss Regiment.