Tustin is a city located in Orange County, California, in the Los Angeles metropolitan area. As of the census of 2010, Tustin had a population of 75,540. The city is located next to the county seat, Santa Ana, and does not include the Tustin Foothills.Because of a top 10% ranking in start-ups and sole proprietors per capita and one of the shortest commutes in Southern California, the city was chosen in 2009 by Forbes as one of the top 25 towns to live well in America.