The sea was named after the Dutch explorer Abel Janszoon Tasman, who in 1642 was the first known person to cross it.

[2] In both Australian and New Zealand English, it is nicknamed the Ditch comparable to the North Atlantic Ocean nicknamed as "the Pond"; for example, "crossing the Ditch" means travelling to Australia from New Zealand or vice versa.

On the South A line joining the southern point of Auckland Island (50°55′S 166°0′E / 50.917°S 166.000°E / -50.917; 166.000) to South East Cape, the southern point of Tasmania.The Tasman Sea's midocean ridge developed between 85 and 55 million years ago as Australia and Zealandia broke apart during the breakup of supercontinent Gondwana.

[7] The Tasman Sea features a number of midsea island groups, quite apart from coastal islands located near the Australian and New Zealand mainlands: The East Australian Current that commences its flow southwards in the tropics of the Coral Sea, near the eastern coast of Australia is the most energetic circulation feature in the south western Pacific Ocean and is a primary means of heat transport from the tropics to the middle latitudes between Australia and New Zealand.

[13] It transpires that while predominantly the location of westerly wind stress is a factor in how far north the formation of the Tasman Front occurs, so is the presence of the New Zealand land mass, as the top of New Zealand defines the furtherest south that the Tasman Front can be split off by the westerly winds.

[13] The East Australian Current sheds eddies on its way south that move south-westward with some known as the Tasman Leakage making it as far westward as the Indian Ocean.

[14] In 1876, the first telegraph cable connecting Australia and New Zealand was laid in the Tasman Sea.