There will be flights between Jersey and Heathrow for the next five years.
Ports of Jersey says the deal follows 12 months of negotiations.
CEO Matt Thomas says it's really good news for islanders and will bring benefits for business and tourism.
"Whether it's travelling to see mum and dad, or whether they are travelling to go on holiday or on business - they can plan with confidence that the UK's major carrier is going to take them to their major hub."
He says it is a significant further step to returning to pre-Covid passenger numbers.
"It will build in the years ahead as we become a much more attractive destination because we are better-connected internationally. At the same time, islanders benefit by being able to get into the hub at Heathrow.".
It's estimated more than two million passengers will travel between Jersey and Heathrow over the five year term of the agreement.
British Airways has been operating the route since Jersey's borders reopened in July 2020 after the airline switched its services from Gatwick. BA operates to 138 destinations across the world from Heathrow.
"The connection with London Heathrow provides connectivity for Islanders as well as enhancing opportunities for both the business and leisure sectors as we build back better; put simply, British Airways and Ports of Jersey are investing in Jersey’s future.
Over the last few years, the relationship between us has gone from strength to strength, and we now have an amazing opportunity to welcome as many people between Heathrow and Jersey as we can.” - Colm Lacey, Chief Commercial Officer at British Airways.
Ports of Jersey says research from Oxford Economics suggests enhanced connectivity from Heathrow is projected to deliver growth in GDP of £123 million per annum by 2025, supporting 1,200 jobs.
“Air connectivity is critical to Jersey’s economic wellbeing and way of life, whether to support tourism, travel on holiday, business, visit friends and relatives in the UK or further afield, to access specialist medical care or university education.
As BA’s global hub, Heathrow also offers the connectivity that Jersey’s business and financial sectors requires, along with the proximity and ease of access to London, which is key to the industry.” - Senator Lyndon Farnham, Economic Development Minister.