The purpose of this study is to determine the level of student learning boredom during online learning and its effect on mathematics learning outcomes through Odd Mid-Semester Examination scores for the 2021/2022 academic year. This research uses quantitative research with the Ex Post Facto method and there is one independent variable,namely online learning boredom and one dependent variable, namely mathematics learning outcomes. The sampling technique in this study used purposive sampling so that the sample used is 38 students from class X OTKP 2 at SMK Negeri 1 Kalianda. The data is collected by means of a literature study, distribution of learning boredom questionnaires and data on Odd Mid-Semester Examination  scores for the 2021/2022 academic year obtained from the mathematics teacher concerned. The data analysis in this study used descriptive statistics and inferential statistics with PearsonProduct Moment correlation analysis, simple regression analysis and analysis of the coefficient of determination.The results of this study indicate that class X students at SMK Negeri 1 Kalianda experience online learning boredom with a low category of 10%, a medium category of 74% and a high category of 16%, especially in Mathematics. This is reinforced by the relationship between online learning boredom and Mathematics learning outcomes. From the acquisition of the Pearson Product Moment correlation coefficient of 0.645, it can be interpreted that there is a strong relationship between online learning boredom and Mathematics learning outcomes with the contribution of online learning boredom to thehigh and low mathematics learning outcomes of 41.5% and 58.5% influenced by other factors outside the study.

Keywords: Online, Learning Outcomes, Study Boredom