The Rentwertshausen–Römhild railway was a single-tracked branch line in the state of Thuringia in central Germany.

It was just under 11 kilometres long and ran from Rentwertshausen to Römhild in the south Thuringian region of Grabfeld.

The legal basis for the line was a state treaty between the Kingdom of Bavaria and the Duchy of Saxe-Meiningen, which was concluded on 16 June 1884.

Because the main line between Mühlfeld and Rentwertshausen was blocked, passenger trains now ran directly from Römhild to Meiningen.

In 1944 four pairs of passenger trains ran daily on this line which was timetable route number (KBS) 417 k. The journey time was about half an hour.