The development of Theory of Mind (ToM) is associated with variables such as language, working memory, and nonverbal cognitive competence. Children on the autism spectrum tend to have difficulties in ToM development, language and communication skills, and working memory. This study investigates relationships between language, working memory, and nonverbal cognitive competence with ToM in children on the autism spectrum. The study involved 40 Turkish children on the autism spectrum. Data collection tools included ToM tasks, the Turkish Early Language Development Test, Raven’s Colored Progressive Matrices, and the Working Memory Scale. As a result of this research, it was found that receptive language, expressive language, nonverbal cognitive competence, phonological loop, and central executive measures had significant relationships with ToM. The phonological loop and central executive measures were direct predictors of ToM. Nonverbal cognitive competence did not directly predict ToM but was mediated by the phonological loop and central executive.