This paper investigates stress patterns in Breton across speakers of different ages and with different linguistic backgrounds. Centuries of contact with French have led to French influence in Breton lexis, phonology and morphosyntax, and Breton's current status as an endangered minority language makes it vulnerable to further change. Additionally, younger ‘new speakers’ of Breton, who have acquired the language through Breton-medium education, are said to transfer features from French into their Breton. Analysis of stress usage shows that older, traditional speakers use stress largely as expected, while there is a greater degree of interspeaker variation among younger, new speakers. These data are used to form a metrical analysis of stress in Breton, taking into account lexical exceptions, loanwords and the variability of younger speakers. Rather than widespread transfer of French stress patterns into Breton, some younger speakers seem to be using two competing stress systems.