On September 9, 10, and 27, pilots who are members of the trade union BALPA will be walking out over a dispute regarding pay.
In a statement on the British Airways website, the airline said: "After many months of trying to resolve the pay dispute, we are extremely sorry that it has come to this.
"Unfortunately, with no detail from BALPA on which pilots would strike, we had no way of predicting how many would come to work or which aircraft they are qualified to fly, so we had no option but to cancel nearly 100 per cent our flights.
"We remain ready and willing to return to talks with BALPA."
They are offering all affected customers full refunds or the option to re-book to another date of travel or alternative airline.
Yesterday (August 8) Gatwick Airport tweeted: "If you are flying with British Airways on or around 9 & 10 September, your flight is likely to be impacted by industrial action. Please do not travel to the airport if your flight has been cancelled. Further information and advice is available from BA."