The objectives of this mixed-method study were to develop strategies for sustainable leadership of school administrators under the Secondary Educational Service Area Office Nakhon Phanom. There were 4 research methods: phase I) identify the components of sustainable leadership of school administrators by interviewing 5 experts and confirming factors by 5 experts, phase II) develop strategies for sustainable leadership in a focus group including 7 people, phase III) validate the appropriateness, feasibility and utility of sustainable leadership development by collected of data which comprised 84 school administrators using multi-stage random sampling, and phase IV) produce a user manual of strategies by 5 experts for validate the appropriateness of user manual. The findings were as follows: I) There were four main components in the sustainable leadership of school administrators, namely 1) depth 2) breadth 3) vision, and 4) media literacy. All of the components have appropriateness at the highest level and feasibility at the high. II) The strategies for the development of sustainable leadership of school administrators comprised a vision, 6 missions, 6 objectives, 7 strategies, 61 operational approaches, and 25 indicators. III) The appropriateness, feasibility, and utility of the strategies for the development of sustainable leadership of school administrators were at the highest level. IV) The user manual of the strategies for the development of sustainable leadership of school administrators obtained the overall appropriateness at the highest level.