BACKGROUND: India's economic development and urbanisation in recent decades has varied considerably between states. Attempts to assess how overweight (including obesity) varies by socioeconomic position at the national level may mask considerable sub-national heterogeneity. We examined the socioeconomic patterning of overweight among adults in India's most and least economically developed states between 1998 and 2016. METHODS: We used state representative data from the National Family Health Surveys from 1998 to 99, 2005-06 and 2015-16. We estimated the prevalence of overweight by socioeconomic position in men (15-54 years) and women (15-49 years) from India's most and least economically developed states using multilevel logistic regressions. RESULTS: We observed an increasing trend of overweight prevalence among low socioeconomic position women. Amongst high socioeconomic position women, overweight prevalence either increased to a smaller extent, remained the same or even declined between 1998 and 2016. This was particularly the case in urban areas of the most developed states, where in the main analysis, the prevalence of overweight increased from 19 to 33% among women from the lowest socioeconomic group between 1998 and 2016 compared to no change among women from the highest socioeconomic group. Between 2005 and 2016, the prevalence of overweight increased to similar extents among high and low socioeconomic status men, irrespective of residence. CONCLUSIONS: The converging prevalence of overweight by socioeconomic position in India's most developed states, particularly amongst urban women, implies that this subpopulation may be the first to exhibit a negative association between socioeconomic position and overweight in India. Programs aiming to reduce the increasing overweight trends may wish to focus on poorer women in India's most developed states, amongst whom the increasing trend in prevalence has been considerable.