Objective: To evaluate the (cost-)effectiveness of online consultations in follow-up of patients with celiac disease (CD). Study design: Multicenter randomized, controlled trial involving 304 patients aged ≤25 years with CD for ≥1 year, randomized to an online (n = 156) or outpatient consultation (n = 148). An online consultation included questionnaires for symptom and growth measurement. Antitransglutaminase-type-2 antibodies were determined using a point-of-care (POC) test. Controls had a traditional consultation with antitransglutaminase-type-2 antibodies testing in laboratories. Both groups completed questionnaires concerning CD-specific health-related quality of life (HRQOL), gluten-free diet adherence, and patient satisfaction. Six months later, participants repeated HRQOL and patient satisfaction questionnaires and the POC test. The primary outcome was anti-transglutaminase-type-2 antibodies after 6 months, and the secondary outcomes were health problems, dietary adherence, HRQOL, patient satisfaction, and costs. Results: The performance of the POC test was inferior to laboratory testing (2/156 positive POC tests vs 13/148 positive laboratory tests; P =.003). Health problems were detected significantly more frequently using online consultation. The detection of growth problems and dietary transgressions was similar. HRQOL (from 1 [good] to 5 [poor]) improved after online consultation (from 3.25 to 3.16 [P =.013] vs controls from 3.10 to 3.23; P =.810). Patient satisfaction (from 1 [low] to 10 [high]) was 7.6 (online) vs 8.0 (controls; P =.001); 58% wished to continue online consultations. Mean costs per participant during the studied period were €202 less for the online group (P <.001). Conclusions: The primary outcome could not be tested because the POC test was unreliable. Nevertheless, our results indicate that online consultations for children and young adults with CD are cost saving, increase CD-specific HRQOL, and are satisfactory for the majority. Trial Registration: Trialregister.nl: NTR3688.