Background: Much of the literature on school transfers has centred on academic adjustment and/or achievement, but school transfers also involve social adaption. Children who are socially anxious or lack emotional self-efficacy are likely to have difficulties with social aspects of the transition. Aim(s): We examined the influence of social anxiety, depressive symptoms, and emotional self-efficacy on (1) pre-transition concerns about the move to secondary school and social threat sensitivity relating to that transition experience, and (2) school and peer connectedness after the school transfer. We also examined whether pre-transition concerns predicted school and peer connectedness after the move. Sample: Year 6 children (10-11 years) from 15 primary schools in Northern England. Method: Children (N = 266) completed a questionnaire in their primary schools before the move to secondary school. A sub-group (n = 156) of those children also completed measures immediately after the move to secondary school and then again 4 months later. Results: Social anxiety influenced pre-transition concerns. Higher emotional self-efficacy was associated with lower social threat sensitivity pre-transition and with reductions over time. Higher emotional self-efficacy also influenced greater social adaption 4 months after the school move. Pre-transition concerns about the move were a good indicator of poorer social adaption later on. Conclusions: Based on the findings, interventions should target social anxiety to reduce pre-transition concerns. Programmes that target emotional self-efficacy are most likely to impact school and peer connectedness.