Pärnu is the fourth largest city in Estonia. Tallinn, the capital city of Estonia, is 128 kilometres (80 mi) north of Pärnu, and Tartu, Estonia's second largest city, is 176 kilometres (109 mi) east of Pärnu. Located in southwestern Estonia on the coast of Pärnu Bay, an inlet of the Gulf of Riga in the Baltic Sea. It is a popular summer holiday resort with many hotels, restaurants, and large beaches. The Pärnu River flows through the city and drains into the Gulf of Riga. The city was served by Pärnu Airport.

The majority of the tourists in Pärnu are Finns, Swedes and Russians.

In 1837, a tavern near the beach was made into a bathing establishment. The establishment accommodated 5-6 bathrooms that provided hot seawater baths in summer and operated as a sauna in winter. The wooden building was burnt down in the course of World War I. In 1927, the present stone building of Pärnu Mud Baths was erected at the same site.

Since 1996 Pärnu has been known as Estonia's Summer Capital.

Starting from 2015 the city of Pärnu hosts the annual Weekend Festival, the largest dance music festival in the Nordic and Baltic region. Stages are headlined by DJs from across the electronic dance music spectrum, with audiovisual support. Some of the past and upcoming artists to perform include Martin Garrix, David Guetta, Avicii, Steve Aoki, The Chainsmokers, Tiësto, Armin van Buuren, Hardwell, Robin Schulz, Afrojack, deadmau5, Knife Party, Desiigner and many more.

Pärnu is also known for its seawall. According to legend, if a couple holds hands while journeying along the wall and kisses at its endpoint they will stay together forever.