As the capital and chief port of the Messenia regional unit, it lies along the Nedon River at the head of the Messenian Gulf.

It was long believed that the area that the city presently occupies was covered by the sea during ancient times, but the proto-Greek and Archaic-period remains (Temple of Poseidon) that were unearthed at Akovitika region prove otherwise.

[8][10] Medieval Kalamata was not a port, as the local coast offered no shelter to ships from the weather, but lay further inland, at the foot of the western outliers of Mount Taygetos.

[8] Following the Fourth Crusade, Kalamata was conquered by Frankish feudal lords William of Champlitte and Geoffrey of Villehardouin in 1205, when its Byzantine fortress was apparently in so bad a state that it could not be defended against them.

[13] In 1292 or 1293, two local Melingoi Slavic captains managed to capture the castle of Kalamata by a ruse and, aided by 600 of their fellow villagers, took over the entire lower town as well in the name of the Byzantine emperor, Andronikos II Palaiologos.

Constable John Chauderon in vain tried to secure their surrender, and was sent to Constantinople, where Andronikos agreed to hand the town over, but then immediately ordered his governor in Mystras not to do so.

[14] In 1298, the town formed the dowry of Princess Matilda of Hainaut upon her marriage to Guy II de la Roche.

[13] In 1358, Prince Robert gifted the châtellenie of Kalamata (comprising also Port-de-Jonc and Mani) to his wife, Marie de Bourbon, who kept it until her death in 1377.

[13] The town remained one of the largest in the Morea—a 1391 document places it, with 300 hearths, on par with Glarentza—but it nevertheless declined in importance throughout the 14th and 15th centuries in favour of other nearby sites like Androusa.

Kalamata remained in Frankish hands until near the end of the Principality of Achaea, coming under the control of the Byzantine Despotate of the Morea only in 1428.

[15][16] Morosini returned in 1685, at the start of the Morean War: on 14 September 1685 the Venetians defeated an Ottoman army before Kalamata, and again plundered and destroyed the town's castle, as it was judged obsolete.

[19] During World War II on 29 April 1941, a battle was fought near the port between the invading German forces and the 2nd New Zealand Division, for which Jack Hinton was later awarded the Victoria Cross.

According to the meteorological station in the nearby airport, Kalamata has a hot-summer Mediterranean climate (Köppen: Csa) with mild, wet winters and hot, dry summers.

A previously disused extension line to the port is now a Railway Park, with old steam engines on display, and a café in the old station building.

Also in the summer months, charter and scheduled flights fly direct to Kalamata International Airport from some European cities.

[33] Local specialities: Kalamata hosts a lot of notable sport clubs with earlier presence in the higher national divisions in Greek football.