Purpose Children with specific language impairment (SLI) are more likely than children with typical language (TL) to exhibit difficulties in word-level spelling accuracy. More research is needed to elucidate the contribution of linguistic knowledge to word-level spelling accuracy in this population. The purpose of this study was to explore the contributions of linguistic knowledge to spelling accuracy in a group of 2nd- to 4th-grade children with SLI and a group of 2nd- to 4th-grade children with TL. Method Participants were 32 children with SLI and 32 children with TL in Grades 2 through 4. Five areas of linguistic knowledge were assessed: phonological awareness, morphological knowledge, orthographic pattern knowledge, mental grapheme representation knowledge, and vocabulary knowledge. Mixed-effects logistic regression models were utilized to address the research aim. Results Mental grapheme representation knowledge was selected as a significant predictor in both models; however, phonological awareness was the only additional significant predictor in the model for children with SLI, whereas morphological knowledge was the only other significant predictor in the model for children with TL. Orthographic pattern knowledge and vocabulary knowledge were not significant for either group. Conclusions The results suggest that spelling instruction and intervention for children with SLI should take linguistic knowledge into account and explicitly relate linguistic knowledge to spelling. Additionally, future research should consider if instructional targets for children with SLI should differ from targets for children with TL and if these findings represent a delay or a disorder in spelling acquisition for children with SLI.