Introduction <p>Long COVID-related fatigue affects a large number of people across the world, with increasing numbers of people experiencing long-term disability as a consequence. We tested the feasibility of a self-help version of a manual osteopathic approach initially developed for people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to treat people with long COVID-related fatigue.</p> Methods <p>Our feasibility study assessed recruitment into a 1:1 randomized controlled trial (RCT) to receive (i) self-help intervention (self-massage, mobility, flexibility, and breathing exercises, and alternating cold and warm packs to the top of the spine) or (ii) wait-list control group. Follow-up was assessed by online surveys at 3 and 6&#xa0;months (indicating retention). Verbal feedback was obtained from participants.</p> Results <p>Of the 138 eligible survey participants, 126 (90.6%) agreed to participate in two RCTs, achieving the required sample size of 100. Follow-up rates of 79.3% and 59.4% were achieved at 3 and 6&#xa0;months, respectively. Improvements in Chalder Fatigue Questionnaire (CFQ) scores were observed in both groups between 0 and 3&#xa0;months (− 4.6 and − 2.9, respectively), to a greater degree in the intervention group (<i>p</i> = 0.01). Feedback showed a cohort keen to engage with the intervention, although some found the intervention onerous at times.</p> Conclusions <p>We have reported the results of a feasibility study examining a potentially beneficial intervention for people with long COVID. There were indications of benefit in a patient group with often intractable symptoms. Based on this feasibility study, we believe that the low-cost self-help intervention in isolation could help support fatigue reduction in some people. This has implications for the treatment of both long COVID and ME/CFS.</p> Trial Registration <p>International Standard Randomized Controlled Trial Number (ISRCTN): 99840264.</p>