Paxos (Greek: Παξός) is a Greek island in the Ionian Sea, lying just south of Corfu. As a group with the nearby island of Antipaxos and adjoining islets, it is also called by the plural form Paxi or Paxoi (Greek: Παξοί, pronounced /pækˈsiː/ in English and [paˈksi] in Greek). The main town and the seat of the municipality is Gaios. The smallest of the seven main Ionian Islands (the Heptanese), Paxos has an area of 25.3 square kilometres (9.8 sq mi), while the municipality has an area of 30.121 km² (11.630 sq mi) and a population of about 2,500.

Paxos lies some 15 km from the southern tip of Corfu and at about the same distance from the town of Parga on the mainland. It is connected by ferry lines from Igoumenitsa and Corfu with Gaios. The island is hilly, the highest point having an elevation of 230 m.

In Greek mythology, Poseidon created the island by striking Corfu with his trident, so that he and his wife Amphitrite could have some peace and quiet.

Paxos is a historical island that has been inhabited since prehistoric times. According to tradition, the Phoenicians were the first settlers on Paxos, and it is believed that the name "Paxos" originated from the Phoenician word "Pax," meaning "trapezoidal." In ancient times, Paxos played a significant role, especially during the First Illyrian War in 229 BC when the Battle of Paxos was fought between the ancient Greek and Illyrian fleets. The account of this battle is documented in The Histories, a work by the ancient historian Polybius.

Paxos has been ruled by various conquerors, including the Romans in the 2nd century BC, pirates during the Byzantine era and Middle Ages, and by Crusaders. Eventually, the Venetians gained control of the island at the end of the 14th century.

During the Napoleonic Wars, the Ionian Islands were occupied by the French and the Russo-Turkish alliance. However, Paxos surrendered to the Royal Navy frigate HMS Apollo and 160 troops from the 2nd Greek Light Infantry from Cephalonia and the 35th Regiment of the Royal Corsican Rangers on February 13, 1814. The United Kingdom established the United States of the Ionian Islands in 1815. In 1864 Paxos, along with the rest of the Ionian Islands, were ceded to Greece following the coronation of George I of Greece.

Paxos lies some 15 km from the southern tip of Corfu, and at about the same distance from the town of Parga on the mainland.

The island is approximately 10 kilometres (6 mi) long and up to 3 kilometres (2 mi) wide, stretching in northwest–southeast direction. Much of the hilly landscape is covered in olive groves. These stretch from Lakka, the harbour community in the north, through Magazia to Gaios, the capital. Coastal communities of Gaios, Lakka and Longos on the east coast are the three main settlements, while the interior features numerous scattered hamlets. The west coast is dominated by steep white, chalky cliffs that are greatly eroded at sea level, and harbour many "blue caves". The highest point of the island is Agios Isavros at an elevation of 231 m. Several islets lie very close to the coast of Paxos: Agios Nikolaos and Panagia protect the harbor of Gaios, while Mongonisi and Kaltsonisi lie off the southeastern tip. Antipaxos lies some 5 km further southeast.