We investigated the relationship between semantic knowledge and word reading. A sample of 27 6-year-old children read words both in isolation and in context. Lexical knowledge was assessed using general and item-specific tasks. General semantic knowledge was measured using standardized tasks in which children defined words and made judgments about the relationships between words. Item-specific knowledge of to-be-read words was assessed using auditory lexical decision (lexical phonology) and definitions (semantic) tasks. Regressions and mixed-effects models indicated a close relationship between semantic knowledge (but not lexical phonology) and both regular and exception word reading. Thus, during the early stages of learning to read, semantic knowledge may support word reading irrespective of regularity. Contextual support particularly benefitted reading of exception words. We found evidence that lexical–semantic knowledge and context make separable contributions to word reading.