Many patients with persistent musculoskeletal pain have difficulty maintaining physical activity (PA) long-term following pain management programmes (PMPs). This qualitative study explored the barriers and facilitators to sustaining PA after PMPs, as well as PA patterns describing long-term activity trajectories. Semi-structured interviews were conducted with 24 individuals with persistent musculoskeletal pain, seven partners/spouses, and eight healthcare professionals (four physiotherapists, two occupational therapists, and two psychologists). Data were analysed using reflexive thematic analysis and mapped to the Theoretical Domains Framework. Five themes were identified: (1) internal drivers for PA maintenance, (2) fitting PA into daily life, (3) symptoms and symptom management, (4) social networks and influences, and (5) environmental influences. These findings mapped onto 13 of the 14 domains of the Theoretical Domains Framework. Four PA patterns emerged: (1) consistently active, (2) initially active but later inconsistent, (3) inconsistently active since PMP, and (4) reduced or unchanged activity levels.