Brittany Ferries is the trading name of the French shipping company, BAI Bretagne Angleterre Irlande S.A. founded in 1973 by Alexis Gourvennec, that operates a fleet of ferries and cruiseferries between France and the United Kingdom, Ireland, and Spain, and between Spain and Ireland and the United Kingdom.

Working with fellow Breton farmers, Gourvennec lobbied for improvements to Brittany's infrastructure, including better roads, telephone network, education and port access.

The company itself began sailings on 2 January 1973 between Roscoff in Brittany and Plymouth in the South West of England, using the freight ferry Kerisnel, a former Israeli tank carrier.

In 1974, Kerisnel was replaced by Penn-Ar-Bed, which carried both passengers and vehicles, and the BAI company adopted the name Brittany Ferries.

On 21 September 2012, Brittany Ferries cancelled sailings indefinitely following two days of wildcat strikes caused by crew members who were unhappy with changes in working terms and conditions.

[6] From late March 2020, due to the ongoing COVID-19 pandemic, Brittany Ferries was forced to cancel all passenger sailings until 15 May 2020 after British government advice was issued against all travel.

It also confirmed the launch of a five-year recover plan following the loss of more than half of its revenue, the consequence of restrictions on passenger traffic in all markets in which it operates.

[9] On 20 July 2021, Brittany Ferries announced at a press conference in Paris that it had secured a charter with Stena RoRo for 2 more E-Flexers.