This study provides a mixed-methods case-study design evaluation of the Leadership in Blended Learning (LBL) program. The LBL program uses blended approaches, including face-to-face and online, to prepare school leaders to implement blended learning initiatives in their schools. This evaluation found that the program designers effectively implemented all four models of blended learning as part of the program. The evaluation findings also suggest that the Leadership in Blended Learning program improved participants' capacity to effectively lead blended learning initiatives in their school, district, or organization. Participants reported that sessions were especially effective in deepening their understanding of planning for and using technology to support professional learning; the role and responsibilities of leadership; definitions, models, and key planning components of blended learning; and traditional vs. new instructional models. Finally, the findings suggest that LBL was largely successful in helping educators apply their learning within their profession settings. Among those who completed the End-of-Program survey, roughly 9 out of 10 participants (88%) indicated that they had made changes in their school or professional practice. When asked if they had applied their learning to support changes the program was designed to address, the majority of participants (57% - 83%) again responded positively. The findings from this paper suggest that using a blended approach can help scale high quality professional development for principals.