Background: Facebook represents a new dimension for global information sharing. Suicidal behaviours and attempts are growingly reported on Facebook. This scoping review explores the various aspects of suicidal behaviours associated with Facebook, discussing the challenges and preventive measures. Methods: PubMed, Google Scholar, and Scopus were searched for related articles published in English up to October 2021, using different combinations of "Facebook" and "suicide". A group of consultant psychiatrists screened the records and read the full-text articles to extract relevant data. Results: Facebook impacts suicidal behaviours in different aspects. Announcing suicides through sharing notes or personal information, which can be helpful in prediction of suicide, and harmful since negatively affects audience. Live-streaming videos of suicide is another aspect, which questions the ability of Facebook to monitor shared contents that can negatively affect the audience. Helping bereaved families to share feelings and seek support online, commemorating the lost person by sharing their photos is another positive impact. Moreover, it can provide real-world details of everyday user behaviours, which are helpful to predict suicide risk, primarily through novel machine-learning techniques, and provide early warning and valuable help to prevent it. It can also provide a timeline of the user's activities and state of mind before suicide. Conclusions: Social media can detect suicidal tendencies, provide support for those seeking help, comfort family and friends with their grief, and provide insights via timelining the users' activities leading to their suicide. The lack of quantitative studies on evaluating preventative efforts on Facebook was one of the limitations. The creators' commitment and the users' social responsibility will be required to create a mentally healthy Facebook environment.