The discourse on online collaborative learning in thesis writing has received less attention despite numerous studies which explored learning in the online milieu. Hence, this study aimed to fathom the Online Collaborative Learning (OCL) experiences in undergraduate thesis writing of Bachelor of Arts in Communication and English Language students in a prime state university in the Cordillera Administrative Region, Philippines. Notably, this study focused on undergraduate students’ benefits, challenges, and suggestions. Employing qualitative phenomenological research, the data were gathered through semi-structured one-on-one in-depth interviews. They were analyzed following the phases of thematic analysis by Braun and Clarke (2006). Ergo, the following themes were generated. First, the benefits included joint responsibility, which envelopes (a) a divided workload and (b) shared ideas and flexible communication. Second, the challenges were composed of external problems that bracket (a) work and school demands, (b) vague instructions, and (c) limited access and member performance issues which involve background knowledge, low quality outputs, and a lack of participation. Finally, the suggestions were engagement particularly recognizing responsibility, group dynamics, and guidance. Based on the findings, recommendations are suggested for future research directions.