Information processing theory suggests that sublexical fluency skills are important to word reading development, but there are few supportive data. This study investigated if sublexical fluency (letter name fluency, letter sound fluency, and phoneme segmentation fluency) contributed to the development of word reading and spelling in 92 kindergarten children. The pattern of findings suggests that, as early as kindergarten, sublexical fluency skills explain a small, but significant, amount of unique variance in literacy outcomes when also considering the influence of accuracy in these skills. Also, growth in sublexical fluency skills is related to both word reading and spelling proficiency at the end of kindergarten. We suggest that knowledge of early literacy skill development may be enhanced by attention to sublexical fluency and that these skills, specifically letter sound fluency, may provide the mechanism that supports early word reading and spelling.