Increasing population density and technological developments resulted in an increase of chlorophenols (CPs) that have been identified as emerging contaminants. CPs can take several routes into the environment, such as industrial waste, pesticides, insecticides, and degradation of complex chlorinated hydrocarbons. CPs have a potential hazard to environmental sources and cause long-term exposure for animals and humans. Determination of CPs in the environment is difficult because of low analyte concentrations and complex matrixes. Thus, developing effective approaches is necessary. Laccases, which are multicopper oxidases capable of oxidizing substituted phenols and benzenediol derivatives, without any cofactor, are used in biosensors due to their biocatalytic properties, eco-friendliness, and efficiency. Carbon nanotubes (CNTs) show excellent electrical conductivity, mechanical strength, and biocompatibility. They are suitable for enzyme immobilization, which can improve stability and catalytic efficiency. This chapter provides a general approach to CNTs based laccase biosensors to detect CPs for environmental, industrial, and pharmaceutical analysis.