This study analyzes language choice, bi- and multilingualism, and gender in a corpus of over 22 million Twitter messages by almost 36,000 authors from the Nordic countries and territories. Author location, gender, and tweet language are identified using a novel method. Three principal findings are discussed: First, gendered preference for particular languages in the Nordics can be explained in part by patterns of gendered migration. Second, a distinct geographical pattern of female/male preference for the national languages of the region and for English is evident for users who are likely native users of a Nordic language: Females are more likely to use English, while males are more likely to use a Nordic language. Third, while high rates of bi- and multilingualism are found across the whole sample, males are more likely to use more than one language in all the Nordic countries/territories. The latter two findings are interpreted in light of sociolinguistic considerations as evidence for incipient language shift towards English for Nordic users on the Twitter platform.