Pulmonary hypertension (PH) is associated with right ventricular pressure overload and atrial remodeling, which may result in supraventricular tachycardias (SVTs). The outcomes of catheter SVT ablation in patients with World Health Organization (WHO) group 1 PH are incompletely characterized. We conducted a retrospective cohort study of all patients with WHO group 1 PH undergoing catheter SVT ablation during a 10-year period at a major academic tertiary care hospital. Baseline patient characteristics and procedural outcomes at 3 months and 1 year were extracted from the electronic medical record. Ablation of 60 SVTs was attempted in 38 patients with group 1 PH. The initial procedural success rates were 80% for atrial fibrillation (AF, n = 5), 89.7% for typical atrial flutter (AFL, n = 29), 57.1% for atypical AFL (n = 7), 60% for atrial tachycardia (AT, n = 15), and 75% for atrioventricular nodal reentrant tachycardia (AVNRT, n = 4). The 1-year post-procedural recurrence rates were 100% for AF (n = 4), 25% for typical AFL (n = 20), 50% for atypical AFL (n = 2), and 28.6% for AT (n = 7). No patients had recurrent AVNRT (n = 2). There were seven (18.4%) peri-procedural decompensations requiring pressor initiation and transfer to intensive care and one (2.6%) peri-procedural death. The study demonstrates that SVT ablation in group 1 PH can be performed relatively safely and effectively, albeit with lower initial success rates and higher risk of clinical decompensation than in the general population. Recurrence rates at 1 year were higher in AF and atypical AFL ablations and similar for typical AFL and AT ablations when compared to the general population.