The Rock Island District (RI) is a Metra commuter rail line from Chicago, Illinois, southwest to Joliet.

In the early 1890s the line was extended north to 89th Street in conjunction with the expansion of the Chicago Terminal Transfer Railroad, and the portion on 99th was removed.

In spring 1981 the C&NW stepped away, and the Northeast Illinois Regional Commuter Railroad Corporation (Metra) was formed to take over operations.

In addition, Chicago Rail Link has rights to operate local freight service on the whole district, and it also uses the line between Gresham Wye and Blue Island[which?]

[7] The overpass proposed by Chicago Region Environmental and Transportation Efficiency Program (CREATE), which cost $142 million to construct, was completed in October 2014.

[9] In October of 2023, Metra announced the order of 16 lightweight Stadler FLIRT Akku electric multiple unit trainsets that would likely be used on the Beverly Branch.

There have been proposals to extend the line from Joliet to LaSalle-Peru in LaSalle County with intermediate stations at Rockdale, Minooka, Morris, Seneca, Marseilles, Ottawa, and several other towns.

[18] In the beginning of 2021, fares on the Rock Island, as well as the Metra Electric District, were cut in half for all passengers as part of a pilot program.