Few studies have assessed the treatment of tardive dyskinesia (TD) in patients with primary mood disorders who are managed with antipsychotics. The effects of once-daily valbenazine on TD were evaluated in adults with a bipolar or depressive disorder. Data were pooled from two 6-week double-blind placebo-controlled trials (KINECT 2 and KINECT 3; 114 mood participants) and a long-term blinded extension study (KINECT 3 extension; 77 mood participants) of valbenazine in adults with TD. Efficacy assessments included Abnormal Involuntary Movement Scale (AIMS) total score (sum of items 1-7), Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD), and Patient Global Impression of Change (PGIC). Safety assessments included treatment-emergent adverse events (TEAEs), Young Mania Rating Scale, and Montgomery-Åsberg Depression Rating Scale. At Week 6, mean improvements in AIMS total score were significantly greater with valbenazine versus placebo (40 mg/day, -3.1 [P < 0.01]; 80 mg/day, -3.5 [P < 0.001]; placebo, -0.9). Significant differences between valbenazine (80 mg/day) and placebo were also found for Week 6 AIMS response (≥50% total score improvement) and CGI-TD response ("much improved" or "very much improved"), but not PGIC response. Sustained improvements in AIMS, CGI-TD, and PGIC were found through 48 weeks. Valbenazine was generally well tolerated, with no unexpected TEAEs, worsening in psychiatric symptoms, or emergence of suicidality. Pooled analyses were conducted post hoc, and neither study was designed to focus solely on mood disorder patients. In participants with primary mood disorders, once-daily treatment with valbenazine was generally well tolerated and resulted in 6-week and sustained TD improvements.