This research aimed to: 1) examine the levels of the administrators’ ethical leadership, public participation, and the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province, and 2) investigate the influences of the administrators’ ethical leadership and public participation on the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province. The sample consisted of 396 people who resided in the local administrative organizations in Waritchaphum District, Sakon Nakhon Province. They were obtained through the stratified sampling method. A questionnaire was employed as a tool for data collection and the statistics used for data analysis included frequency, percentage, mean, standard deviation, and multiple regression analysis. The research revealed these results: 1. The overall ethical leadership of the administrators in the local administrative organizations in Waritchaphum District was at the high level ( =3.99). Likewise, the public participation in the administration of the local administrative organizations in Waritchaphum District, as a whole, was also at a moderate level ( =3.50). However, the overall effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province was at a moderate level ( =3.26). 2. In terms of the administrators’ ethical leadership, these aspects significantly influenced the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province at .01 statistical level: ethical guidance and long-term care. At the same time, these aspects significantly influenced the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province at .05 statistical level: integrity and role clarity. Altogether, these variables could be used for the correct prediction of the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province 38.00% (R² = .380). As for the public participation, these aspects significantly influenced the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province at .01 statistical level: benefit-sharing and decision-making. Meanwhile, evaluation participation significantly influenced the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province at .05 statistical level. Altogether, these variables could be used for the accurate prediction of the effectiveness of promoting and developing the public services of the local administrative organizations in Waritchaphum District, Sakon Nakhon Province 43.30% (R² = .433).