Pulmonary hypertension (PH) is associated with a substantial symptom burden, reduced exercise capacity and impaired quality of life (QoL). Although exercise is recommended as an adjunct to medical therapy, physical activity (PA) levels remain low and access to specialist, centre-based programmes is limited throughout Europe. This study aimed to develop and evaluate a patient-centred, theoretically informed, remotely delivered home-based PA and exercise intervention for adults with PH. Following Medical Research Council guidance for developing complex interventions, virtual semi-structured interviews and thematic analysis was used to explore the attitudes, knowledge, preferences and support needs of 19 adults with PH. Fear of overexertion, physical harm and breathlessness strongly constrained physical activity. Participants reported receiving inadequate exercise guidance and expressed a preference for individualised home-based exercise supported by clinicians, monitoring and accountability. These qualitative findings informed a single-arm feasibility study involving 20 clinically stable adults with PH (80% female; age 49.9 ± 15.9 years). Participants completed a 10-week remotely delivered programme comprising induction sessions, education, aerobic, resistance and respiratory training, a PA manual and logbook, wearable activity monitoring and health coaching. Feasibility, safety, acceptability, PA, functional capacity, QoL and self-efficacy were assessed; 19 participants completed follow-up. No intervention-related adverse events occurred. Adherence to prescribed aerobic, resistance and respiratory training was 95%, 91% and 94%, respectively. Six-minute walk distance increased by 72 m (p<0.001), daily steps by 2,349 (p<0.001), and moderate-to-vigorous PA from 9.3 to 23.6 min/day (p<0.001). Sedentary waking time decreased, while lower-limb function, PH-specific QoL and most self-efficacy domains improved. Participants valued the programme’s convenience, flexibility, accessibility and professional support.  This fully remote, home-based intervention was safe, feasible and acceptable, with promising improvements in PA, functional capacity and QoL. It may help address important barriers to centre-based programme participation. A multicentre randomised controlled trial is warranted to establish clinical effectiveness and long-term sustainability.