BACKGROUND: :To inform optimal management of HIV viremia on TLD, we examined viral load (VL) outcomes of a large cohort of adult PLHIV on TLD in Nigeria. METHODS: :We conducted a retrospective study of adult PLHIV who had ≥1 VL after initiating TLD during January 2017-February 2023. VLs were categorized as undetectable (≤50 copies/mL), low low-level viremia (LLV, 51-199 copies/mL), high LLV (200-999 copies/mL), virologic nonsuppression (VLNS, ≥1000 copies/mL), and virologic failure (VF, ≥2 consecutive VLNS results). Among patients with ≥2 VLs on TLD, we described how viremia changed over time and examined virologic outcomes after VF. We identified predictors of subsequent VLNS using mixed-effects logistic regression and conducted planned contrasts between levels of VL result and regimen types. RESULTS: :Analysis of 82,984 VL pairs from 47,531 patients demonstrated viral resuppression to ≤50 copies/mL at follow-up VL in 66.7% of those with initial low LLV, 59.1% of those with initial high LLV, and 48.9% of those with initial VLNS. Of 662 patients with a follow-up VL after VF, 94.6% stayed on TLD; of which 57.8% (359/621) were undetectable at next VL without regimen change. Previous low LLV (aOR 1.74, 1.56-1.93), high LLV (aOR 2.35, 2.08-2.65), and VLNS (aOR 6.45, 5.81-7.16) were associated with increasingly higher odds of subsequent VLNS, whereas a previously undetectable VL (aOR 1.08, 0.99-1.71) on TLD was not. CONCLUSIONS: :Despite increased odds of subsequent VLNS, most PLHIV with detectable viremia on TLD, including those with VF, will resuppress to an undetectable VL without a regimen change.