Nafplio or Nauplio (Greek: Ναύπλιο, romanized: Náfplio) is a coastal city located in the Peloponnese in Greece.

Founded in antiquity, the city became an important seaport in the Middle Ages during the Frankokratia as part of the lordship of Argos and Nauplia, held initially by the de la Roche following the Fourth Crusade before coming under the Republic of Venice and, lastly, the Ottoman Empire.

[4] The oldest reference to Nafplio appears to be in the so-called "Aegean List" from the Mortuary Temple of Amenhotep III, dating to 14th century BCE, where it is recorded as npry (nw-py-r-y).

[10] During the Middle Ages, several variants were used in Byzantine Greek, including Náfplion (Ναύπλιον), Anáplion (Ἀνάπλιον), and Anáplia (Ἀνάπλια).

Also during the early modern period, but this time under Ottoman rule, the Turkish name of the town was Mora Yenişehir, after Morea, a medieval name for the Peloponnese, and "yeni şehir", the Turkish term for "new city" (apparently a translation from the Greek Νεάπολη, Italian Napoli).

[13] The area surrounding Nafplio has been inhabited since ancient times, but few signs of this, aside from the walls of the Acronauplia, remain visible.

Pausanias noticed the ruins of the walls of a temple of Poseidon, certain forts, and a fountain named Canathus, by washing in which Hera was said to have renewed her virginity every year.

It became part of the lordship of Argos and Nauplia, which in 1388 was sold to the Republic of Venice,[22] who regarded it as one of their most important places in the Levant.

[23] The city, under Venetian rule twice repelled Ottoman attacks and sieges, first by Mehmed the Conqueror during the Ottoman–Venetian War (1463–1479) and then by Suleiman the Magnificent.

The city was strengthened by building the castle of Palamidi, which was in fact the last major construction of the Venetian empire overseas.

Due to its architectural legacy, its proximity to the capital, Athens, and its mild and pleasant climate it attracts visitors all-year round, and it is the most popular destination for weekend or one-day excursions.

Apart from tourism agriculture is a very important sector and the city is also surrounded by a fertile irrigated plain and produces oranges, lemons, peaches, apricots, olives and almonds.

The Port of Nafplio is used only for bulk cargo due to its insufficient depth and also hosts a great number of leisure ships during the tourist season.

Since 1952, the town has been served by public bus (KTEL Argolida), which provides daily services to all destinations in region as well as other major Greek centers such as Athens.

Nafplio maintains its own distinct traditional architectural style with many colourful buildings around the old town, influenced by the Venetians, due to their domination between 1338–1540 and during the Kingdom of the Morea and to a much lower degree by the Ottomans.

It is one of the few Greek cities to have been spared the widespread destruction of traditional architecture during the process of antiparochí, due to the efforts of the archaeologist Evangelia Protonotariou Deilaki, whose actions went against the prevailing trend of the post-war era.

They are related mostly with the modern history of Nafplio, such as the statues of Ioannis Kapodistrias, Otto of Greece and Theodoros Kolokotronis.