Background: Bipolar disorder (BD) is characterized by recurrent (hypo)manic and depressive episodes, alternating with euthymic states in which patients are relatively symptom free. Besides clinical recovery, it is important to also strive for improvement of mental well-being and personal recovery. One prominent field focussing on the improvement of well-being is positive psychology. However, studies assessing the effects of positive psychology or personal recovery interventions for people with BD are scarce and have used weak methodological designs. The study described in this protocol article aims to assess the effectiveness of a multicomponent positive psychology intervention ("Living well with bipolar disorder") adjusted for people with BD in the euthymic phase to improve well-being and personal recovery. Method: The study concerns a pragmatic randomized multicenter trial. The principle objective of the study is to assess whether the positive psychology intervention offered to BD patients in remission in addition to usual care (CAU) is more effective than CAU. The study will include 112 participants randomized to either the experimental condition receiving the intervention in addition to CAU or the control condition receiving CAU. The study population are patients with BD I or II in the euthymic phase. The inclusion criteria are 1) diagnosis of BD I or BD II, 2) between the ages of 18-65, 3) four or more supportive sessions in the last year, and 4) only residual depressive or manic symptoms. Patients are excluded if they are in a depressive or manic episode, have current addiction problems or have optimal levels of well-being. Measurements take place at baseline, post-intervention and follow-up 6 and 12 months from baseline. Outcomes of measures include positive well-being, personal recovery, psychopathology, self-compassion, positive relationships, dampening of positive affect and relapse. Discussion: The outlined study will be the first RCT examining the effects of a multicomponent positive psychology intervention for patients with bipolar disorder. Several limitations, including generalizability of the results and possible attrition issues, are discussed in advance. Trial registration: This study has been registered in the Netherlands Trial Register (NTR6729) on 12 October 2017.