This study aimed to examine the teacher motivation and morale in Bangkok Metropolitan Administration schools, the school effectiveness, the relationship between the factors of teacher motivation and morale in performing their jobs that influence school effectiveness, and the development of guidelines for enhancing teacher motivation and morale in relation to school effectiveness. In the study, the researcher employed a mixed research methodology. In the initial phase, questionnaires were used to collect data. The population consisted of Bangkok Metropolitan Administration school teachers who served their duty in 2022. A multistage random sampling selected 375 persons in total. Mean, percentage, and standard deviation were applied as descriptive statistics. In the last phase, the researcher conducted in-depth interviews with seven experts selected through purposive sampling to gather their perspectives on the applicability, possibility, and usefulness of the the guidelines for enhancing teacher motivation and morale in relation to school effectiveness. The data was analyzed using a content analysis method. According to the findings, the multiple correlation coefficient was 0.760 (R = 0.760 at the 0.05 level of significance. The predictive coefficient or predictive power of 57.7 percent (R2 = 0.577), with the regression coefficient () arranged in descending order: 1) Professional Success ([beta]=0.321) 2) Career Growth ([beta]=0.238) 3) School Policies ([beta]=0.162) 4) Workplace atmosphere and environment ([beta]=0.102) 5) Governance Aspects ([beta]=0.096). The forecast equations can be generated using the regression coefficients of the predictors in raw score (b) and standard score () as follows: In raw score (unstandardized score) form, the forecast equation is Y' = 1.391 + 0.255 (x 6 )0.183 (x 10 x 10) 0.124 (x 5 (x 5 )0.050 (x 3 (x 3 )0.075 (x 2 (x 2). Standardized score forecast equations Zy = 0.321 (x 6) + 0.238 (x 10) + 0.162 (x 5) + 0.102 (x 3) + 0.096 (x 2). The researcher also devised a guideline containing nineteen recommendations for enhancing the top five teacher motivation and morale factors that influence school effectiveness. There are 19 guidelines for improving teacher morale, which affects school effectiveness.