This longitudinal study explored Theory of Mind (ToM), self-perceptions, and teacher ratings of peer relations of 91 children (52 females, ages 6-8?years) drawn from two schools situated in a mainly Euro-Canadian, middle socioeconomic status, semi-rural central Canadian context. ToM, self-perceptions, and teacher ratings of peer relations were assessed at Time 1 (T1, M?=?6 y 2 m) and 2?years later at Time 2 (T2, M?=?8 y 5 m). Findings showed that ToM scores and perceptions of global self-worth and physical appearance significantly increased with time across both genders. Positive longitudinal associations were found between teacher ratings of sociable peer relations at T1 and children's T2 moral self-perceptions. A positive longitudinal correlation was found between T1 ToM and T2 teacher ratings of anxious/fearful peer relations. Individual variation in ToM at age 6 predicted teacher ratings of anxious and fearful behaviours in 8?year olds. In contrast, teacher ratings at age 6 did not predict ToM ability in 8?year olds. Educational implications for social and emotional competencies are discussed.