Professional experience elicits enduring effects on teacher self-efficacy (TSE); however, despite a growing understanding of early TSE formation, limited quantitative studies have been conducted. No research has applied a person-centred method, meaning personal variation or simultaneity in the integration of different TSE sources has been neglected. This person-centred study investigated TSE levels and perceived sources of TSE of 289 pre-service teachers (PSTs) following a four-month placement using latent profile analysis. Three profiles of perceived TSE source combinations, namely lowest-in-all sources (24.22%), highest-in-all (25.95%), and medium (49.83%) profiles, were reported. Significant differences in TSE and variations in the predictability of sources were examined among the profiles. Implications and limitations are discussed.