Preparing school administrators to support effective instruction of English language learners (ELLs) is an important dimension of today's school leadership programs, yet often difficult to enact. This paper reports a comprehensive needs analysis of a school leadership advanced certificate program carried out by Teaching English to Speakers of Other Languages (TESOL) and school administration faculty. This contributed to a comprehensive understanding of the needs of faculty and candidates in their beliefs and experiences with ELL pedagogy. Implications for collaboration with TESOL faculty to strengthen more effective instruction for ELLs are discussed.