Pomona is a city in Los Angeles County, California, in the eastern San Gabriel Valley. As of the 2000 census, the city population was 149,473. In 2005, its population was estimated as 160,815 . Pomona is the 5th largest city in Los Angeles County (after Los Angeles, Long Beach, Glendale, and Santa Clarita).

Pomona is best known as the location of California State Polytechnic University, Pomona (Cal Poly Pomona). This university was established on the site of breakfast cereal magnate W.K. Kellogg's massive ranch located on the city's west side. It is also the home of the Los Angeles County fairgrounds. While a fair in the nation's most populous county might seem quaint, Cal Poly is one of several major agricultural research facilities in the state, and the fair's livestock exhibits are a noted attraction. (Other major California agriculture schools include California Polytechnic State University San Luis Obispo, Fresno State, UC Davis, and Chico State.)

Western University of Health Sciences is located in downtown Pomona, with programs ranging from veterinary medicine to nursing to osteopathic medicine.

Pomona is not, as is often assumed, the site of Pomona College. Although this elite liberal arts institution was founded in the city in 1887, its campus has been in neighboring Claremont since 1889.

Since the 1980's, Pomona's newest neighborhood Phillips Ranch, experienced rapid growth with demands of new housing units increased. Homes are still being built in the hilly area between Downtown and Diamond Bar. Today, Phillips Ranch is nearly all residential.