The purpose of this study was to increase student activity and learning outcomes by applying peer tutor learning methods combined with interactive case methods in online learning mode through Electronic Learning Aid (ELENA) and Zoom meeting. This study was carried out with a classroom action research (CAR) design in three cycles of implementation. This study was carried out in the even semester of 2020/2021 in the Cost Accounting course. Data collection methods used are documentation, observation, and tests. Student learning activities in online learning through ELENA and Zoom meetings have been recorded to show changes and improvements in the quality of student learning activities. The data analysis method used is quantitative descriptive analysis. The application of the peer tutor learning with the interactive case methods has been going well through the Zoom meeting and ELENA and is able to have an impact on student activities and learning outcomes in the Cost Accounting course. The increase in student learning activities can be seen in the increased ability of students to ask questions, provide responses or answers, and express opinions or ideas during lectures. Student learning outcomes also experienced a significant increase, which was 7.5%. Students who act as tutors can carry out their duties well.