Orthographic knowledge, the general ability to learn, store, and use information about the orthographic form of words (Stanovich & West, 1989), is a crucial skill for supporting literacy. Although the development of first language (L1) orthographic awareness is impacted by the characteristics of a learner's L1 writing system, relatively little is known about what impact the L1 may have on second language (L2) orthographic awareness. In this study, English language learners from three L1s (French, Hebrew, Mandarin Chinese), plus L1 English speakers, were tested on their English spelling knowledge using a word-pseudohomophone discrimination task. In addition to allowing for the cross-linguistic comparisons, items were designed to examine whether learners had differing performance on pseudohomophones (misspellings) that targeted vowels versus consonants. Consistent with previous research (e.g., McBride-Chang, Bialystok, Cong, & Li, 2004), the L1 Chinese speakers had the highest (L2) accuracy, followed by the L1 Hebrew and the L1 French speakers. The participants from non-alphabetic languages (Hebrew and Chinese) had significantly lower accuracy on items with misspellings involving vowels compared to consonants, and the size of the vowel-consonant accuracy difference varied substantially across L1 groups. The results demonstrate that the characteristics of a learner's L1 writing system, particularly the existence of vowel and consonant graphemes, impact the development of L2 orthographic knowledge and sensitivity to different types of word misspellings.