The Carnegie Library in El Reno, Oklahoma is the oldest Carnegie library in Oklahoma that is still functioning as a library. Constructed in 1903, it was listed on the National Register of Historic Places in 1980 and has been in continuous use as a library since its opening.

The main feature of the Classical Revival structure is its two-story portico with four ionic columns. The only structural addition to the library since its construction was a fireproof archives room built in 1964.