Thessaloniki, Thessalonica, or Salonica is the second-largest city in Greece and the capital of Macedonia, the nation's largest region.

Thessaloniki is Greece's second major economic, industrial, commercial and political centre, and a major transportation hub for the rest of southeastern Europe; its commercial port is also of great importance for Greece and its southeast European hinterland. It has been traditional for the country's Prime Minister to set out his government's policies for each coming year in a speech at the annual Thessaloniki International Trade Fair.

Thessaloniki retains several Ottoman and Jewish structures as well as a large number of Byzantine architectural monuments. The city has hosted an annual International Trade Fair, the Thessaloniki International Film Festival, and the largest bi-annual meeting of the Greek diaspora.

The city was founded around 315 BC by the King Cassander of Macedon, on or near the site of the ancient town of Therma and twenty-six other local villages. He named it after his wife Thessalonike, a half-sister of Alexander the Great (Thessalo-nikē means the "victory over the Thessalians"). It was an autonomous part of the Kingdom of Macedon. After the fall of the kingdom of Macedon in 168 BC, Thessalonica became a city of the Roman Republic. It grew to be an important trade-hub located on the Via Egnatia and facilitating trade between Europe and Asia. The city became the capital of one of the four Roman districts of Macedonia.

Landmarks

• The White Tower of Thessaloniki (Greek: Λευκός Πύργος Lefkos Pyrgos), widely regarded as the symbol of the city.
• The Arch and Tomb of Galerius is more commonly known as the "Kamara" and ornately decorated, crafted with a reddish-coloured stone.
• The Upper Town or Ano Poli is what remains of Ottoman Thessaloniki, with beautiful wooden houses overhanging the winding streets all the way up to the Eptapyrgio at the top of the city. The Ano Poli also contains some of the city's oldest and most important churches, particularly Osios David, St. Nicholas Orphanos and the Vlatades Monastery.
• The Church of Aghios Demetrios is the most important church in the entire city. Lying above the remains of the agora and the Roman Forum, the church has three side-chapels, a museum, and underground catacombs that also include Saint Demetrios' imprisonment chamber; he is the patron saint of the city.
• OTE Tower, a TV tower is the center of the Thessaloniki Expo Center. A revolving restaurant offers spectacular views of the city.
• The waterfront is Thessaloniki's major draw. The promenade of Nikis Avenue runs from the White Tower of Thessaloniki to the giant palace that is now a ferry terminal, and plentiful cafés, restaurants and shops line the waterfront.
• The Arch and Tomb of Galerius, or the Church of Aghios Georgios, is a circular church lacking the classic Orthodox iconostasis. The church is built upon former Roman and Greek pagan ruins.
• Aristotelous Square extends all the way from Nikis Avenue on the waterfront to the Church of Panayia Halkeion. The square, shaped like a bottle, is lined with tall archondika, or mansions of the affluent, that have now been converted to shops and hotels. A large park lies at the north end of the square, and Thessaloniki's thriving old market is just one block away to the east and west.
• The Church of Aghia Sofia, also located in the city center, includes the large church and paved alleyways that make the few blocks around it widely known.
• The extensive Byzantine walls of the Upper City (Ano Poli) and the Heptapyrgion or Yedi Kule citadel.
• The Kyvernion (little Palace); former residence of the King and Queen of Greece; in the Karabournaki area, in Eastern Thessaloniki
• The modern Concert Hall of Thessaloniki in the East side of the city, near the Poseidonion sports center.
• Thessaloniki International Trade Fair held every September, organised by Helexpo.