Positive education is characterized by applying positive psychology interventions (PPIs) within educational settings. Increasing evidence suggests that PPIs can help increase well-being and reduce depressive symptoms in general and clinical populations. However, there is less evidence that PPIs are similarly effective within complex school environments. The study aimed to (1) examine the effectiveness of an evidence-informed positive education pilot program (PEPP) delivered within an Australian public high school and (2) use an implementation science framework to explore factors impacting the planning, delivery, practice, and success of program activities. The study used a non-randomized waitlist design (n = 143), and provider (teacher), recipient (student), intervention (PEPP), organizational (school), and contextual factors were systematically explored through a mixed methods approach. Findings suggest the PEPP was not related to increases in well-being or resilience, but may have buffered students from declining mental health during the school year. Recipient outlook, organizational support, stakeholder input, and provider enthusiasm and understanding were all thought to impact program outcomes. By exploring the practice of a positive education intervention from an implementation perspective, challenges and opportunities of positive education in the real world can be identified.