Fuente: Ultrasounds Extraction Byproducts Citrus food waste raised global concerns due to its environmental burden. In the last two decades, researchers and industries have invested considerable efforts in addressing this issue worldwide. Through conventional and novel extraction / fractionation techniques, several bioactive compounds could be recovered from citrus food waste. This chapter delves in the recent approaches that demonstrated a potential in upcycling citrus food waste into added-value ingredients for the formulation of functional foods. A comprehensive overview of the principal bioactive compounds found in this waste such as phenolic compounds, dietary fiber, essential oil, and pectin was established. These bioactive compounds emerged as promising ingredients in the dairy, bakery, meat, beverages, and other food industries by playing crucial roles including antioxidant, anti-inflammatory, antimicrobial, prebiotic, encapsulating agent, edible packaging material. This was demonstrated by enhancing the chemical and nutritional composition of dairy, meat, or bakery products through incorporation of bioactive compounds extracted from citrus food waste. Therefore highlighting the opportunities offered by citrus food waste, particularly as a valuable source of bioactive compounds which promote food safety and food quality.