Introduction: Patients with plaque psoriasis often have nail psoriasis, which is difficult to treat. Ixekizumab (IXE) and ustekinumab (UST) are biologics with established efficacy in nail psoriasis. We present post hoc data from a head-to-head trial of IXE and UST (IXORA-S) to examine the efficacy in nail psoriasis in patients with moderate-to-severe plaque psoriasis over 52 weeks. Methods: In IXORA-S, randomised patients received IXE (N = 136) or UST (N = 166) per label for 52 weeks. Eighty-four (61.8%) and 105 (63.3%) of the patients treated with IXE or UST, respectively, had baseline fingernail psoriasis (Nail Psoriasis Severity Index [NAPSI] > 0); of these, 54 (64.3%) and 63 (60.0%) patients, respectively, had significant baseline fingernail psoriasis (defined as NAPSI ≥ 16 with ≥ 4 fingernails involved). The proportion of patients achieving NAPSI = 0, a NAPSI score change from baseline and correlations in Psoriasis Area of Severity Index (PASI) and NAPSI improvement over 52 weeks were examined. Results: Progressive improvement occurred in both treatment groups over 52 weeks. Statistically significantly more patients achieved NAPSI = 0 with IXE versus UST by week 16–20, and the proportions continued to increase through week 52 among patients with baseline nail psoriasis (61.9 vs. 28.6%, respectively; P < 0.001), including those with significant nail psoriasis (57.4 vs. 17.5%, respectively; P < 0.001). Similar results were observed for NAPSI score improvement from baseline to week 52. Interestingly, the presence of nail psoriasis was associated with lower skin response with UST but not with IXE. Conclusions: Ixekizumab was superior to UST in the clearance of nail psoriasis, with earlier improvement continued through 52 weeks regardless of baseline nail severity. Trial Registration: ClinicalTrials.gov identifier; NCT02561806.