The East Arm Little Calumet River, also known as the Little Calumet River East Branch, is a 22.1-mile-long (35.6 km) portion of the Little Calumet River that begins just east of Holmesville, Indiana in New Durham Township in LaPorte County and flows west to Porter County and the Port of Indiana-Burns Waterway.

The Calumet River is a system of heavily industrialized rivers and canals in the region between the south side of Chicago, Illinois, and the city of Gary, Indiana. Historically, the Little Calumet River and the Grand Calumet River were one, the former flowing west from Indiana into Illinois, then turning back east to its mouth at Lake Michigan at Marquette Park in Gary. Now the system is part of the Chicago Area Waterway System and through the use of locks flows away from Lake Michigan to the Cal-Sag Channel.