The Roum Fault is a north-south left-lateral fault running about 35 kilometres through southern Lebanon, branching off the main Dead Sea Transform south of the restraining bend that forms Mount Lebanon. It is one of several splays that share the plate-boundary motion between Arabia and the Sinai block across the Lebanese restraining bend.
The fault carries a portion of the transform's left-lateral slip at a low rate, cutting through hilly terrain and offsetting streams and ridges along its trace. Its role in partitioning strain around the bend makes it important for understanding how motion is distributed through Lebanon.
The Roum Fault is the leading suspect for the destructive 1837 Safed earthquake, which killed thousands in southern Lebanon and Galilee. Because it passes near populated areas and links to the highly active Dead Sea system, it is a focus of seismic hazard studies for the region.