BackgroundOlder cancer survivors often value quality of life (QOL) over survival. Life‐space mobility (LSM), defined as the individual's spatial geographic mobility range, is an important QOL indicator in older adults with chronic illnesses; however, this relationship is unexplored in older cancer survivors.MethodsWe examined the longitudinal associations and causal relationships between LSM and QOL in 153 older cancer survivors (≥65 years) from the University of Alabama at Birmingham (UAB) Study of Aging. LSM was assessed using the UAB Life‐Space Assessment‐Composite score (LSA‐C), and QOL was assessed by the SF‐12 Mental Component Score (MCS12) and Physical Component Score (PCS12) at 0 (study entry), 6, 18, 36, 54, and 72 months. We examined the causal relationship between LSM and QOL using a cross‐lagged panel model (CLPM).ResultsThe cohort (n = 153) was 76 years old on average and predominantly White (58%), female (58%), and married (55%). Longitudinal analyses found LSM decreased over time (p < 0.0001), and this decrease was associated with decreased QOL (PCS12, p < 0.0001, MCS12, p < 0.0001). In the CLPM causal analysis, lower LSM resulted in worse PCS12 (p < 0.001), but not worse MSC12.ConclusionsRestricted LSM resulted in worse physical QOL over 72 months in a sample of 153 older cancer survivors. Developing and evaluating interventions to preserve greater LSM could be a promising approach to improving QOL.