[eng] The pronoun THEY has recently gained recognition as a non-binary pronoun, i.e. one which refers to individuals who do not exclusively identify as male or female, and that can also be expressed by neopronouns such as ZE or XE. (Scelfo 2015; Bradley 2020). One of the spheres in which it is more likely to find users who specify the pronoun(s) which they identify with is online spaces. For this reason, previous studies have focused on the choice of gendered pronouns (Jian et al. 2022) but, to the best of my knowledge, no study has focused exclusively on the choice of non-binary pronouns in social networks. To help bridge this void, this thesis aims to analyze the usage of different non-binary pronouns in Twitter profiles and to identify the intra- and extra-linguistic factors which might condition their variation. The methodology used, therefore, is corpus-based and data were extracted by means of Followerwonk, a Twitter analytics platform from which I collected almost 2.000 tokens from Twitter users located in different US regions. The results show that many different neopronouns are used, though they remain quite marginal as opposed to THEY the most commonly used non-binary pronoun among Twitter users, which is quite often accompanied by HE or SHE. Other intralinguistic factors such as collocation with particular sexuality terms have not been found relevant, as was also the case with geographical and sociological factors, which do not seem to play a significant role in non-binary pronominal variation.