This paper presents an acoustic analysis of front rounded vowels (FRVs) in the dialect spoken in the Shetland Islands, the northernmost locality of the British Isles. FRVs are typologically marked and estimated to occur in only 6.6% of the world’s languages [I. Maddieson, in Haspelmath et al. The World Atlas of Language Structures (2005)]. Their occurrence in the Shetland dialect is, at least partly, attributable to a Scandinavian substratum language. There is significant variation across the archipelago regarding several aspects such as (1) the number of lexically contrastive FRVs, (2) phonetic quality (close to half‐close), (3) contrastive length, and (4) lexical distribution and support. This paper presents an investigation of three speakers from one locality in which FRVs have retained firm lexical support. The issues addressed concern the dialect’s overall acoustic vowel space (based on F1, F2, and F3), the position of FRVs within the acoustic space, and what the contrasts among FRVs and other adjacent vowels appear to rest on acoustically. Special focus is directed to phonetic contexts that support the greatest number of vowel contrasts and display the most crowded acoustic vowels spaces.