This study investigated the role of lexical skills and executive functioning on L1 Dutch and L2 English phonological awareness in children enrolled in bilingual Dutch/English kindergarten in The Netherlands (n = 95) and monolingual Dutch kindergarten (n = 83). Participants had an average age of 5 years and 10 months and completed tasks on phonological awareness, lexical skills (vocabulary and lexical specificity), and executive functioning (sustained visual and auditory attention, behavioural self-regulation, and verbal short-term memory) in the L1 Dutch and the L2 English. Dutch phonological awareness was predicted by self-regulation and verbal short-term memory. English phonological awareness was directly predicted by Dutch phonological awareness and visual sustained attention. The results highlight the importance of executive functioning such as sustained attention, behavioural self-regulation and short-term memory in first and second language learning in kindergarten, and support cross-language transfer effects from L1 to L2 phonological awareness among bilingual learners.