Relatively little is known about the importance of phonological and orthographic processing skills for reading and spelling in monolingual and bilingual adults. We compared these underlying skills, using a series of phonological and orthographic tasks, in English monolingual (n = 28), English first language and Chinese second language bilingual (n = 21), and Chinese first language and English second language bilingual adults (n = 22) who were equally proficient in reading and spelling English, and examined the contributions of these skills to English word reading and spelling for each group. The results showed group differences in phonological processing, with English monolingual adults having better phonological skills than both groups of bilingual adults. No significant group differences were found for orthographic processing. Regression analyses showed phonological skills were a unique predictor of English word reading for both bilingual groups, but not for the English monolingual group. Orthographic skills were a significant predictor of English word spelling, but only for the English monolingual adults. This suggests there may be a long-lasting influence of being exposed to two contrasting languages on skills underlying literacy in bilingual individuals.