The airline will run six services a week from Heathrow Terminal Five to the Iranian capital Tehran, starting on 14 July. Daily flights will start on 30 October.
BA first flew between London and Tehran in 1946 but services stopped in October 2012.
Iran has been scrambling for Western trade and investment since economic sanctions were lifted in January.
The country’s tourism industry has also been hoping for a boost as American and European visitors feel more confident travelling to the state.
BA head of network planning Neil Cottrell said Iran was a large, growing economy and brilliant business city.
“The recent lifting of sanctions opens up exciting new prospects for Iran as a tourist destination and with its rich heritage, unique architecture and world-class food it’s unsurprising Tehran is tipped to be a popular destination for 2016," he said.
The Foreign Office relaxed its travel advice for Iran last year, previously warning against travel to the whole country.
British nationals are still advised to keep a low profile, as security forces may be suspicious of travellers with UK connections.
The British embassy in Tehran also reopened last August, for the first time since 2011.
Those who make the trip will be able to see spectacular sights like the ancient Safavid city of Isfahan and the Persian empire’s capital Persepolis.
BA’s fares from London to Tehran start at £384 in economy, rising up to £3,763 in first class.