We examine the association of community linguistic diversity with non-spousal sexual activity in Uganda. We conducted a survey on rates of sexual contact in last 12 months among 1709 respondents age 18–60 living in Uganda in early 2001. Households were selected at random from Demographic and Health Survey (DHS) 2000 household sampling frame listings in 12 districts and 120 clusters. Household listings described the principal language spoken by every household in the cluster. Sexual contact was reported by 26 vs. 13% of unmarried women in multilingual vs. monolingual clusters respectively. Extramarital sexual contact occurred for 29 vs. 16% for married men in multilingual vs. monolingual clusters respectively. These results were robust to multivariate models which included confounders such as urbanity, and cluster distance to market places, cinemas, and transportation. Our results suggest a robust association between residence in a multilinguistic community and higher rates of non-spousal sex.