Plano (pron.: /ËpleÉªnoÊ/) is a city in the state of Texas, located mostly within Collin County. The city's population was 269,776 at the 2010 census, making it the ninth most populous city in the state of Texas (Corpus Christi is ranked at #8 and Laredo is ranked at #10) and the 70th most populous city in the United States. Plano is located within the metropolitan area commonly referred to as the DallasâFort Worth metroplex. The city is home to many corporate headquarters: Alliance Data, Cinemark Theatres, Dell Services, Dr Pepper Snapple Group, Ericsson, Frito-Lay, HP Enterprise Services, Huawei, J. C. Penney, Pizza Hut, Rent-A-Center, Traxxas, and Siemens PLM Software.