The Museum Archives documents the history of the Los Angeles County Museum from its founding in 1910 to the present. The collection includes photographs, departmental papers, research papers, ephemera, publication, architectural plans, newspaper clippings and original artwork.

The Homestead Museum collection includes a diverse array of items from Los Angeles and the Los Angeles Region covering the general period of 1830 to 1930 and includes ephemera, maps, photographs, printed works, and three-dimensional everyday artifacts. The Homestead Museum is a participant in the LAAS and ONE Archives Hidden Histories project.