The purpose of this research is to examine the effect of vertical and shared e-leadership approaches on self-regulated learning skills, motivation and group collaboration processes (group cohesion, group atmosphere, and group transactive memory system) in online project-based learning. The study was carried out according to a factorial experimental design (2 × 2) and mixed methods approach was used. The study was conducted on 41 teacher candidates randomly assigned to vertical and shared e-leadership groups. As a data collection tool; Self-Regulated Learning Scale, Motivation Scale, Transactive Memory Scale, Group Atmosphere Scale, Group Cohesion Scale, and a semi-structured interview form were used. Research findings indicate that there is no statistically significant difference between vertical and shared e-leadership groups in terms of self-regulated learning skills, motivation and group collaboration processes. In other words, both leadership approaches were found to be useful in the management of groups in online project-based learning. The qualitative findings of the research reveal that there are some advantages and disadvantages in both approaches. In this context, the shared e-leadership approach is determined to be useful especially in terms of fostering the sense of belonging to the group by sharing the leadership role within the group, ensuring a fair distribution of responsibility and workload among the group members. The vertical e-leadership approach was found to be useful in providing communication, cooperation and coordination among the group members thanks to the group leader, ensuring the planned progress of the group works.