The survey conducted by Which? was based on responses from 11,625 passengers who had flown from the UK.
It saw the carrier receive a score of just 52%, compared with 67% a year ago.
The lower ranking comes after a year in which BA ended its free catering for passengers travelling in economy class on short-haul flights.
The airline was awarded just two stars for its food and drink and was given the same poor rating for its seat comfort and value for money.
It means BA has fallen behind Tui and Thomas Cook for the first time.
Channel Islands carrier Aurigny Air Services was awarded the number one spot with 80%, gaining four stars from passengers for its boarding process, cabin environment and customer service.
Ryanair and Vueling, which is owned by BA’s parent company IAG, ranked joint last, with a customer score of 45%.
Meanwhile in the long-haul table Singapore Airlines ranked number one for the second year running, at 88%, and received full marks in several categories.
United Airlines ranked the worst of the long-haul airlines at 39%, followed by American Airlines at 46%.
Rory Boland, Which? travel editor, said: "Passengers are telling us that there are many different ways to be a great airline, but providing great service at an acceptable price is a must have.
"BA’s poor customer satisfaction shows it clearly needs to step up its game in a year that has been beset with problems.
"From the food and drink on offer, to the poor value for money of the journey itself, the airline has a lot of work to do to improve the experience that passengers associate with the airline."
In response, a BA spokesperson told Sky News: "British Airways is a premium airline committed to customer choice.
"We offer customers the biggest network from London’s most central airports, a loyalty programme with huge benefits and the best punctuality record of the three big short-haul operators from the capital.
"We also give our growing numbers of customers a wide choice of fares and services."
