Non-Hodgkin lymphoma (NHL) constitutes a significant portion of the global cancer burden and associated mortality. However, a comprehensive understanding of NHL's scale and trends remains limited, underscoring the need for evidence-based epidemiological research to inform healthcare decisions and planning effectively. Incidence, mortality, and disability-adjusted life-years (DALYs) estimates, along with 95% uncertainty intervals (UIs), were derived from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. This study delineates NHL epidemiology by sex and age categories globally, regionally, and nationally. It examines NHL burden trends from 1990 to 2021 across various dimensions, analyzes burden breakdowns by population size, age structure, and epidemiologic changes, assesses cross-country inequalities using WHO-endorsed health equity methodologies, and projects NHL burden changes over the next 30 years. Notably, it explores how social development levels influence NHL epidemiological patterns and utilizes frontier analysis to evaluate health potential across different countries and regions. In 2021, 604,554 individuals (95% UI: 558,229-648,746) were diagnosed with NHL, and NHL-related deaths totaled 267,061 (95% UI: 246,095-288,696). From 1990 to 2021, the total number of newly diagnosed cases rose from 255,668 (95% UI: 242,749-272,801) to 604,554 (95% UI: 558,229-648,746); deaths grew from 146,657 (95% UI: 136,931-160,542) to 267,061 (95% UI: 246,095-288,696); and DALYs surged from 5,199,945 (95% UI: 4,797,150-5,770,129) to 7,766,063 (95% UI: 7,130,942-8,486,078). At the regional level, Andean Latin America had the highest ASIR, with 20.2 cases per 100,000 people (95% UI 16.13-25.26). At the national level, Peru recorded the highest age-standardized incidence rate (24.00 [95% UI 17.61-31.1] per 100,000). High-SDI regions exhibited sharp declines in age-standardized DALYs rates. Cross-country inequality increased from 22.68 DALYs per 100,000 in 1990, to 66.26 in 2021. Population growth appeared to have the most significant influence on incidence rates. Frontier analysis reveals that middle and upper-middle SDI countries have greater potential for health improvements. It is projected that the age-standardized rates (ASR) for mortality and DALYs will continue to decline up to 2051. Over the past three decades, NHL burden has intensified, necessitating increased health resources to address challenges associated with aging populations. Currently, high-SDI countries experience the highest NHL incidence and mortality rates, while developing nations with moderate to low-middle SDI levels must enhance efforts to manage the rising NHL burden effectively.© 2025. The Author(s).