The Rusenski Lom (Bulgarian: Русенски Лом [ˈrusɛnski ˈɫɔm]) is a river in northeastern Bulgaria, the last major right tributary of the Danube. It is formed by the rivers Beli Lom (White Lom) and Cherni Lom (Black Lom), the former taking its source south of Razgrad and the latter southeast of Popovo.

The source of the Beli Lom at 43°24′N 26°40′E / 43.400°N 26.667°E / 43.400; 26.667 and 360 metres (1,180 ft) above sea level is provisionally accepted as the point where the Rusenski Lom starts. Before they merge, the two rivers have a length of 114.2 kilometres (71.0 mi) for the Cherni Lom and 122.8 kilometres (76.3 mi) for the Beli Lom and a drainage basin of 1,550 square kilometres (600 sq mi) and 1,310 square kilometres (510 sq mi) respectively. Both rivers primarily run northwestwards, with the Beli Lom going west at Senovo and the Cherni Lom flowing northeast after Shirokovo, as the two rivers get closer to merge east of Ivanovo. The Rusenski Lom empties into the Danube at the city of Ruse, which gives the river its name. The total length from the source of the Beli Lom is 196.9 kilometres (122.3 mi). The altitude of the mouth is 18 metres (59 ft) above sea level.

The Rusenski Lom flows through Rusenski Lom Nature Park.