David Charles Collier, commonly known as D. C. Collier or as "Charlie" and sometimes given the honorary title of "Colonel", was an American real estate developer, civic leader, and philanthropist in San Diego, California during the early years of the 20th century. He is best known as the organizer and director of San Diego's Panama California Exposition (1915–16). He was also a prime developer of several areas of San Diego as well as La Mesa and Ramona. In his day he was described as "San Diego's foremost citizen."