In online social networks individuals are given the option to reveal on their online profiles some personal information about themselves including, among others, their home loca- tion that, if specified, is typically referred to with a toponym. A toponym disclosed by an individual on her profile, or self- reported toponym (e.g., “London”), is often ambiguous and may be interpreted as the name of different geographic lo- cations (“London, U.K.”, “London, Ontario, Canada”, “Lon- don, Arkansas, USA”). The determination of the right inter- pretation of a self-reported toponym is challenging because the profile of an individual usually lacks the contextual in- formation that can be used to disambiguate the toponym. In this paper, we propose LocusRank, an algorithm for the disambiguation (or resolution) of the self-reported to- ponyms in online social network profiles. More precisely, Lo- cusRankchooses the right interpretation of a self-reported toponym of an individual by using the (possibly ambigu- ous) self-reported toponyms of her friends. Besides, Locus- Rankcan also be used to infer with good accuracy the home location of profiles that do not even have a self-reported to- ponym. We evaluated LocusRankwith good results on a dataset of profiles obtained from two real social networks, namely Flickr and LiveJournal.