Cortland is a city in Trumbull County, Ohio, United States located on the eastern shore of Mosquito Creek Reservoir. Walnut Run is the creek that runs through town. The population was 6,830 at the 2000 census. It is part of the Youngstown-Warren-Boardman, OH-PA Metropolitan Statistical Area. Cortland became a village in 1874 with the construction of a railroad depot. It became a city in 1980 when its population exceeded 5,000 people.
The area was once known as Baconsburg, after Samuel Bacon, who built a sawmill and several buildings in the area during the early 19th century.
Cortland's school district is known as Lakeview. It has one elementary school, one middle school, and one high school (Lakeview High School).