Southern Pacific 5021 is an SP-2 class 4-10-2 steam locomotive built in 1926 by ALCO at their Schenectady, New York, shops.

Southern Pacific donated 5021 to the Railway and Locomotive Historical Society on 8 March 1956.

Following this, 5021 was stored in the roundhouse of the Atchison, Topeka and Santa Fe Railway.

While it was stored, a possible excursion career for 5021 was being arranged by the Santa Fe, but the plans were dropped.

As of 2023, 5021 is on permanent display at the Fairplex railway exhibit in Pomona, California.