The most problematic issue related to textile wastewater is dyes. The occurrence of toxic and carcinogenic compounds in textile dyes creates aesthetic problems and affects the aquatic ecosystem. Dyestuff removal methods include physical, chemical, and biological-based technology. For a more environmentally friendly process that is low cost, produces less sludge, and needs a lesser amount of chemicals, biological treatment is preferable technology. To get maximum effectiveness and efficiency, integrations/ hybrids consisting of several technologies are commonly used. This chapter is dedicated to exploring the potential of biological technology to remove dyes from wastewater, especially dyes used in textile industries. This chapter briefly discusses dyes' characteristics, their utilization, and toxicity. Deeper reviews about the biodegradation potential of dyes are elaborated, along with a discussion about biodegradation mechanisms and reviews of either lab-scale or fullscale applications of biological-based technology for dyes treatment. Lastly, this chapter also gives future insight into the biological treatment of dyes.