Objective: The purpose of this study is to examine the relationship between teachers' cyber hygiene and their digital data security awareness. Method: The sample of the study consists of 7,170 volunteer teachers randomly selected from among teachers in different branches working in public and private schools in eighty-one provinces affiliated to the Ministry of National Education of the Republic of Turkey. Descriptive analysis was used to summarise the general characteristics of the data, multiple regression analysis was used to examine the effect of more than one independent variable on a dependent variable, Pearson Correlation analysis was used to evaluate the relationship between the variables, and a Kolmogorov-Smirnov test was used to check the normality distribution of the continuous variables. Findings: It was determined that the male teachers had higher cyber hygiene and digital data security awareness levels than the female teachers. As age increased, the teachers' cyber hygiene levels decreased and their digital data security awareness increased. The teachers' professional seniority, location, social network and internet usage experiences, daily internet and social network usage time and the number of social media accounts they had affected their cyber hygiene and digital data security awareness levels. In addition, it was determined that teachers who used the Internet for positive purposes had higher cyber hygiene and digital data security awareness compared to others. Conclusion: The results of the study show that there is a moderate positive relationship between the teachers' cyber hygiene levels and their digital data security awareness levels.