Dinuba is a city in Tulare County, California, United States. The population was 24,563 at the 2020 census, up from 21,453 at the 2010 census. I…Dinuba is a city in Tulare County, California, United States. The population was 24,563 at the 2020 census, up from 21,453 at the 2010 census. It is part of the Visalia-Porterville metropolitan statistical area. The Alta District Museum is located in Dinuba in a restored railroad station; the museum has a collection of materials that illustrate local history.