The main purpose of this study was to examine the effect of employeesâ€™ performance appraisal on their job satisfaction with the Moderator of Personality traits in Ethiopian Airlines. During conducting this study the researcher applied Descriptive and explanatory research designs, as well as a quantitative research approach, was applied. The population of the study consisted of employees of the Ethiopian Airline working in Addis Ababa. The appropriate sample has been drawn by applying stratified random sampling. The primary(from the respondent) and secondary data(from the report of the Ethiopian airlinesthus, internet, and other documented materials) sources were used for this research. A self-administered questionnaire was designed to collect relevant information from the selected 165 respondents. Among these 150 questionnaires were returned and analyzed using Statistical Package of Social Science (SPSS) SPSS version 23 and a process micro written by Dr. Andrew F... The percentage, mean and standard deviation of descriptive analysis were employed. The inferential analysis including Pearson correlation and multiple linear regressions was also employed. The study indicated that analysis of the states of employee performance appraisal in Ethiopian Airlines was practiced was done using means and standard deviations at moderate extent which means practice it or itâ€™s applied neutrally(2.5-3.49 moderate extent). In addition, the research found that four BIG FIVE Personality Traits variables have a substantial and positive relationship with employee job satisfaction. Openness to new experiences, conscientiousness, extroversion, and agreeableness are the four moderate factors. Neuroticism, on the other hand, was found to be inversely associated with employee work satisfaction. Furthermore, the study discovered that, in terms of the predicting power of independent variables, the employee's performance appraisal method had to predict the power of airline work satisfaction.