Lorain is a city in Lorain County, Ohio, United States. It is located in Northeast Ohio on Lake Erie at the mouth of the Black River, about 25 miles (40 km) miles west of Cleveland. As of the 2020 census, the city had a population of 65,211, making it Ohio’s ninth-largest city, the third-largest in Greater Cleveland, and the largest in Lorain County by population.

According to local executive records, the city began as an unincorporated village acknowledged before 1834 as “Black River Village”, and was renamed in 1837 as “Charleston.” According to 19th-century historians, the further name was rejected by its own citizens, who continued to use Black River Village. The village was incorporated as Lorain in 1874 and became a city in 1896. The first mayor was Conrad Reid, who took office on April 6, 1874. The municipal boundaries incorporated most of the former Black River Township judicial boundaries, and portions of the Sheffield Township, Amherst Township, and Brownhelm Township judicial borders.

The 1924 Lorain–Sandusky tornado hit the city upon Saturday, June 28, 1924. The tornado formed higher than the Sandusky Bay during the late afternoon hours and hit Sandusky, where it killed eight people and destroyed 100 homes and 25 businesses. After disturbing east over Lake Erie for several miles, the tornado subsequently struck Lorain, killing 72. Among the dead were 15 people inside a collapsed theater, which makes it the worst tornado-related death toll from a single building in Ohio. Eight people were next killed inside the Bath House near the location where the tornado came onshore.

According to the United States Census Bureau, the city has a total area of 24.14 square miles (62.52 km), of which 23.67 square miles (61.31 km²) is house and 0.47 square miles (1.22 km) is water.