The use of online dating applications (apps) among men who have sex with men (MSM) has become a common occurrence in today’s digital age. One example is Grindr, the first location-based dating app of its kind, which was launched in 2009. This marked a new phase of online dating, currently facilitating connections for gay, bi, and curious men in almost every country in the world based on attraction and physical proximity. Grindr celebrated its 10th anniversary this year, yet little is known about users’ motivations and usage patterns, or its potential impact on users’ mental health in the United Kingdom (UK). The aim of the present research was to investigate whether problematic Grindr use existed, and if so, to explore the relationships between problematic Grindr use and psychosocial well-being based on Griffiths’ (2005) six-component model of behavioural addiction. Grindr users (N = 832; M age = 34 years) anonymously self-completed questionnaires via an online survey, which was, advertised on Grindr, social networking sites (Facebook & Twitter), and specific LGBT forums. The results from the cross-sectional study highlight that those experiencing problematic Grindr use differ significantly from those who do not, and this was evident across all study variables. The participants reported lower psychological well-being, greater psychological distress, increased minority stress and neglect of social life as compared to those for whom usage was non-problematic. The most common reason for using Grindr was for sexual experience, followed by the desire to connect with other people with the same sexual orientation to pass time or for entertainment purposes. Problematic Grindr use was also strongly related to using the app for sexual encounters. The study discusses implications for practice and policy, as well as for Grindr’s operators.