This document discloses algae-derived flexible foams, whether open-cell or closed- cell, with inherent antimicrobial and flame resistant properties, wherein a process of manufacturing includes the steps of: harvesting algae-biomass; sufficiently drying the algae biomass; blending the dried algae biomass with a carrier resin and various foaming ingredients; adding an algal-derived antimicrobial compound selected from various natural sulfated polysaccharides present in brown algae, red algae, and/or certain seaweeds (marine microalgae); and adding a sufficient quantity of dried algae biomass to the formulation to adequately create a fire resistant flexible foam material.