With the rate of both domestic and international migration steadily increasing, the psychological impact of residential migration remains largely unexplored. Attachment, the emotional bond we establish with those close to us, and sense of belonging, the feeling of connectedness to a community, may be vulnerable to frequent migration. This study investigates the association between individuals’ early attachment style, sense of belonging, and migration history. A large international sample (N = 465) aged between 18 and 50 years old (M = 21.85; SD = 4.48), completed a survey on early attachment primary attachment style questionnaire (PASQ), sense of belonging (SOBI), and migration. Results comparing non-movers (n = 240) to domestic movers (n = 52), international movers (n = 109), and domestic−international movers (n = 64), indicate important group differences related to early attachment and its relationship to one’s sense of belonging. Moreover, insecure attachment was associated with increased migration early in life and, more in general, predictive of a negative sense of belonging later in life. Implications for both research and practice are discussed.