COVID-19 driven lockdown has affected air quality worldwide. Changes in air pollutants concentration, Air Quality Index (AQI), and associated Excess Health Risk (ER%) were assessed using satellite data of before (2019), and during (2020) COVID-19 periods in the industrially, agriculturally developed and highly populated area of Haryana in the northern region of Indo-Gangetic Plains. Parameters such as Aerosol Optical Depth (AOD), Particulate matters (PM), Sulphur Di-Oxide (SO 2 ), Nitrogen Di-Oxide (NO 2 ), Carbon Mono-oxide (CO), and Methane (CH 4 ) were derived using satellite data and validated using ground-based observations (n = 23). The coefficient of correlation (r) 0.91, 0.90, 0.95, 0.73, 0.81 and 0.80 were established with AOD, PM 2.5 , PM 10 , SO 2 , NO 2 and CO, respectively. Significant reduction (p \ 0.005) in the concentration of air pollutants, viz. 38% in AOD, 55% in PM 2.5 , 61% in PM 10 , 31% in SO 2 , 10% in NO 2 , 5% in CO and 1% in CH 4 were observed during lockdown. Significant (p \ 0.00) improvement in air quality was observed due to a 44% reduction in pollution level, which led to the reduction in ER% by 71%, which is quite significant. AQI and ER% from satellite and ground showed a high r 2 i.e. 0.88 and 0.99 respectively, suggesting the potential application of satellite data for periodic AQI and ER% assessment.