There are a lot of things students have to do in a day, which is why time management or lists of things to get done are important for them in order to have a good quality. Sleep is the time where they can recharge their energy for the next day. In order to get things done to their full potential, we need to have a good rest at night. It’s a sure thing that different people have different amounts of sleep or the time they go to bed each night. This also applies to secondary school students in Thailand, where they have varied amounts of sleep hours and may consequently affect their time management. Thus, our study aims to find out the correlation between sleep quality and time management of secondary school students in Bangkok. To determine the correlation of the factors, we conducted a cross-sectional survey. All data was collected by sending out a survey questionnaire about sleep quality and time management to secondary school students in Bangkok. The data from 216 participants was then analyzed. The outcomes from Pearson’s correlation test reveal a positive correlation between the assigned variables, which indicates that increasing sleep hours improve time management of the students. This study would put into picture that time management does affect students’ sleep quality and may potentially be put to use backing up potential changes that could be made to our country’s educational system