Longgang City is situated in the southern part of Wenzhou, on the coast of the East China Sea. It nestles on the southern bank of the Aojiang River, one of the eight major river systems in Zhejiang Province. The city is located at the intersection of two national strategically-significant areas: the Yangtze River Delta and the Economic Zone on the West Side of the Straits, sharing its northern and southern borders with Cangnan County and Pingyang County respectively.

Established as a town in October 1983, Longgang has undergone a legendary and historic development from a small fishing village to a farmer-built city, then an industrial city, and ultimately a county-level city. With an approval from the relevant authorities for designating it as a county-level city in August 2019, upgraded Longgang City was founded on September 25th of the same year. Longgang City is currently the only county-level city in the country that has implemented an administrative management system reform known as "large department system and flat management structure."