Arsenic (As) is a metalloid that is mostly found in soil and water. The presence of As over permitted levels becomes poisonous and harmful to living creatures, making it a major global concern. Because the plants are sessile and acquire As as well as critical minerals and water through their roots, they are more vulnerable to arsenic poisoning and the resulting stress. Arsenic and phosphorus share many physical and chemical properties, and they frequently compete to generate physiological anomalies in biological systems that lead to further stress. A fall in yield and a loss in plant biomass are early markers of arsenic’s proclivity to generate toxicity in plants. This is accompanied by significant physiological changes, including an immediate oxidative surge, followed by critical biomolecule oxidation. The phytohormone auxin is essential for plant growth and regulates a variety of developmental processes. The vast array of processes plants use to manage auxin levels, the transit of auxin through the plant, the evolving view of auxin-signaling systems, and various interactions between auxin and arsenic stress are all discussed in this chapter. Interactions between plant hormones and environmental signals are critical for maintaining root development flexibility in the face of constantly changing environmental conditions. This review outlines the nature of arsenic’s influence on plants, the physio-biochemical systems that have developed to deal with As stress, and the mitigation techniques that can be used to minimize the detrimental effects of As through auxin supply.