In 2013 Spielmann and colleagues defined fear of being single as “an entailing concern, anxiety or distress regarding the current, or prospective experience of being without a romantic partner” (Spielmann et al., 2013, p. 1050). Previous research proves it a meaningful construct when it comes to assessing romantic relationships as it predicts the tendency to prioritize relationship status over relationship quality and settle for less. The present study examines the connection between fear of being single and demographic characteristics, personality traits (the Big Five model), and feelings of loneliness using the Fear of Being Single Scale (Spielmann et al., 2013), whose first Czech version was prepared, the NEO Five-Factor Inventory (Hřebíčková & Urbánek, 2001) and the UCLA Loneliness Scale (Kumstátová, 2014; Russel, 1996). 247 Czech adults joined the research. Results have shown that women and involuntary singles reported a significantly higher level of the fear of being single in comparison to men and voluntary singles. Moreover, the fear of being single proved to be significantly negatively correlated with Openness to Experience, Consciousness, and Extraversion and significantly positively related to Neuroticism.