Carlsbad is a coastal resort-town in northern San Diego County, California. According to the state Department of Finance, the city had a total population of 90,271 in 2003. Carlsbad was incorporated in 1952, in large part to generate sufficient funding to connect with the water pipeline running through San Diego County, but also to avoid being annexed by Oceanside. Carlsbad apartments for rent comparison page shows most up to date rent information on Carlsbad apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.