The airline and operator beat the likes of Premier Inn, Brittany Ferries and Liverpool John Lennon airport to the accolade, which it has now claimed four times in the past seven years.
"Congratulations to Jet2 on its win,” said Which? chief executive Anabel Hoult. "The Which? Awards judging standards are incredibly high, so to be named as a winner is a huge achievement - something only achieved by the best of the best.”
The Which? judges’ criteria span the consumer champion’s own testing, brand reliability and data from its customer satisfaction surveys.
"Jet2’s high-quality service means it has far better customer scores and star ratings than its main rivals and this is why we’ve named it the Best Travel Brand for the third year running,” Hoult added.
Jet2 was also recognised as a Which? Recommended Provider in seven other categories – including airlines, beach and resort holiday providers, and family holiday providers.
Steve Heapy, Jet2.com and Jet2holidays chief executive, said: “We are enormously proud of this latest accolade, and we remain totally committed to the customer-first approach which has resulted in this success.
“Our team of amazing colleagues set the benchmark for exceptional customer service, and it is great to see that recognised by customers and the experts at Which?”
The airline and operator was, though, beaten to the Customer Service Brand of the Year award by Zen Internet, which was praised by the Which? judges for resisting an industry trend towards mid-contract price hikes.
Other winners at the ceremony in London earlier this week included Samsung, Honda and LG.
