The Middle Atlantic League (or Mid-Atlantic League) was a lower-level circuit in Americanminor league baseball that played during the second quarter of the 20th century.
The Middle Atlantic League played from 1925 through 1951, with the exception of three seasons (1943–45) when the loop suspended operations during World War II. The league primarily featured clubs based in the U.S. states of Pennsylvania, Ohio and West Virginia, although it had a team in Maryland and, in its final season, one in New York. Its longest-tenured team, in Johnstown, Pennsylvania - the Johnnies - existed for 19 seasons. Its final champion was the 1951 Niagara Falls Citizens.
Throughout its 24-year history, the Middle Atlantic League was a Class-C level, one rung up from the lowest classification, Class-D.
Elmer M. Daily was president of the league through 23 years of its existence.