Selenium (Se) is an essential micronutrient for humans with critical biological functions [1]. Se deficiency affects millions of people, aggravating health problems, such as cancer and cardiovascular diseases [2,3]. This challenge can be overcome by indoor vertical farming conjugated to microgreen production and agronomic biofortification with Se. In this sense, this study aimed to assess the biofortification of white Swiss chard (Beta vulgaris subsp. cicla) microgreens with two inorganic forms of Se under indoor vertical farming and determine phenolic compound, betalain, organic acid, free sugar, and mineral element profiles through chromatographic and spectroscopictechniques. Microgreens were grown in a walk-in growth chamber equipped with LED lamps under controlled conditions and irrigated with a TriPart® Grow NPK 3-1-6 nutrient solution supplemented with different concentrations (10, 20, 40, and a mix of 20 µM) of sodium selenate and sodium selenite. Seeds were sown in polystyrene trays filled with vermi