Background: Overweight and obesity are global public health problems. Overweight or obesity is estimated to cause 4 million deaths, 3.9% of all Years of Potential Life Lost (YPLL) and 3.8% of all Disability Adjusted Life Years (DALYs). Overweight or obesity also leads to conditions such as diabetes and hypertension. It has been shown that teachers have a greater occurrence of overweight or obesity than the general population. This study aimed to determine the prevalence of overweight or obesity among primary and secondary school teachers and to assess factors associated with these problems in Moshi Municipality, Kilimanjaro region, Tanzania.Methods: This was a cross sectional study in which data was collected using a modified WHO-STEPS Survey tool. Data cleaning and analysis were conducted using STATA version 14.0. Frequency and percentage were used to summarize categorical data while mean/median with their respective measures of dispersion were used to summarize continuous data. The Modified Poisson regression model was used to determine factors associated with overweight or obesity among primary and secondary school teachers. The effect was estimated by Prevalence Ratio with 95% confidence intervals and P-value less than 5% considered to be statistically significant. Results: A total of 968 teachers were included in this study with median (IQR) age of 37, (32-48) years. Most of the participant were female (69.7%) about (51.6%) were secondary school teachers. Overall, the prevalence of overweight or obesity was 72.7%. Teachers who were 35+ years had a 27% (aPR: 1.27; 95%CI: 1.1 – 1.4; p<0.0001) greater prevalence of overweight or obesity than those below the age of 35. Female teachers had a 43% higher prevalence of overweight or obesity than male teachers (aPR: 1.43; 95%CI: 1.3 – 1.7; p<0.0001). Persons with a positive history of smoking had only 1% higher prevalence of overweight or obesity, however this was not statistically significant. Conclusion: The Prevalence of overweight or obesity was high, suggesting the need for early intervention with lifestyle changes among teachers in Moshi Municipal. There is an urgent need to design lifestyle interventions targeting overweight or obesity among teachers - especially female teachers and those aged 35+.