Background and Objective: The increased burden of multimorbidity is impacting the lives of people worldwide, restricting the ability of individuals to live autonomously and leading to a poorer quality of life. Improving or maintaining a good quality of life can be an important coping mechanism for individuals living with multimorbidity and functional limitation. This study assessed how multimorbidity affects the trajectories in functional limitation and quality of life as well as the relationship between these two trajectories in a sample of middle-aged and older adults. Methods: Longitudinal prospective data came from the survey of health, ageing, and retirement in Europe, conducted in Luxembourg between 2013 and 2020, distributed across two age cohorts: 50-64 years old (n=897) and 65 years old and over (n=688). Multimorbidity was defined as the co-existence of two or more chronic conditions. Functional limitation was assessed by the summated score from the (instrumental) activities of daily living scales. Quality of life was assessed by the control, autonomy, self-realization and pleasure scale. We used latent growth curve modelling techniques to conduct the analysis. Results: Our results suggest that, throughout the life course, middle-aged and older adults living with multimorbidity experienced poorer quality of life, were at a higher risk of functional limitation, and had a higher number of functional limitations than those without multimorbidity. At baseline and across time, functional limitation had a negative impact on quality of life. We also found that the impact of multimorbidity on functional limitation and quality of life varies across the life course. Conclusions: The previously observed cross-sectional associations between multimorbidity, functional limitation, and quality of life are more persistent and can affect adults over the life course. Any future research on the interrelationship between multimorbidity, functional limitation, and quality of life should assess these effects separately for middle-aged and older adults.