This thesis examines language variation and change in a context of minority language revitalisation. In particular, I concentrate on young fluent speakers of Scottish Gaelic, a minority language of Scotland that is currently undergoing revitalisation. Data from three groups of speakers are presented, older speakers in the Isle of Lewis, a Gaelic heartland area in north-west Scotland, adolescent Gaelic-speakers in Lewis learning the language in immersion schooling; and adolescent Gaelic-speakers in immersion schooling in Glasgow, an urban centre where Gaelic has not traditionally been spoken as a widespread community language. The sociolinguistic analysis examines potential language changes, explores patterns of linguistic variation, and uncovers the role that Gaelic plays in identity formation for each of the participants. In order to gain an insight into the role of Gaelic in different speakers' lives, I report on ethnographic studies carried out in Lewis and in Glasgow. The phonetic analysis then explores patterns of variation in the production of laterals, vowels, and tone and intonation. The results indicate large differences between the speech of older and adolescent speakers in Lewis, while differences between young speakers in Lewis and Glasgow suggest that Glasgow Gaelic is developing as a phonetically and socially distinct variety of the language. For example, older speakers in Lewis speak Gaelic as a partial tone language, unlike young people in Lewis and in Glasgow. Differences are also present between young people in Lewis and in Glasgow, such as in vowel acoustics, the production of the lateral system, and intonation patterns. The developments detailed in this thesis are the result of a complex interaction between the internal sound structure of Gaelic, language contact with varieties of English, identity construction, and differing conceptions of the self. All of these factors are conditioned by the status of Gaelic as a minority endangered and revitalised language. In exploring these avenues, I advance an account of language variation and change and apply it to a context of minority language revitalisation.