Indianapolis and St. Louis Railroad

Cleveland, Cincinnati, Chicago and St. Louis Railway

Big Four (red) and New York Central system (orange) as of 1918
Locale	Illinois, Indiana, Michigan, and Ohio
Dates of operation	1889–1930
Successor	New York Central
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Headquarters	Indianapolis, Indiana

The Cleveland, Cincinnati, Chicago and St. Louis Railway, also known as the Big Four Railroad and commonly abbreviated CCC&StL, was a railroad company in the Midwestern United States. It operated in affiliation with the New York Central system.

Its primary routes were in Illinois, Indiana, Michigan, and Ohio. At the end of 1925 it reported 2391 route-miles and 4608 track-miles; that year it carried 8180 million net ton-miles of revenue freight and 488 million passenger-miles.

The railroad was formed on June 30, 1889 by the merger of the Cleveland, Columbus, Cincinnati and Indianapolis Railway, the Cincinnati, Indianapolis, St. Louis and Chicago Railway and the Indianapolis and St. Louis Railway. The following year, the company gained control of the former Indiana, Bloomington and Western Railway (through the foreclosed Ohio, Indiana and Western Railway and through an operating agreement with the Peoria and Eastern Railway).

In 1906 the Big Four was acquired by the New York Central Railroad, which operated it as a separate entity until around 1930. The Big Four's lines were later incorporated into Penn Central in 1968 with the merger of New York Central and the Pennsylvania Railroad. Penn Central declared bankruptcy in 1970, and in 1976 many of Big Four's lines were included in the government-sponsored Conrail. Conrail was privatized in 1987 and in 1997 was jointly acquired by CSX and Norfolk Southern.