Triclosan (TCS) is a broad-spectrum antimicrobial disinfectant widely used in pharmaceuticals and personal care products (PPCPs). Due to the extensive usage of PPCPs, TCS inevitably entered the environment and posed harmful effects on the ecosystem. Phytoremediation is an attractive approach to remove TCS from the environment. Genetic engineering of plants can be employed to strengthen phytoremediation capacity. In this study, a gene of a nanobody specific to TCS was transformed into Arabidopsis thaliana ( A. thaliana) to enhance the plant absorption of TCS. Two transgenic lines, the T-S-C line with nanobody expression throughout the plant and the T-S-P line with nanobody expression dominant in the roots, were constructed. The expression of nanobody in A. thaliana alleviated the phytotoxicity of TCS. T-S-C and T-S-P exhibited obviously stronger tolerance to TCS toxicity than the wild type (WT), in either a solid medium system or a hydroponics system. Under the stress of TCS, the seedlings of both transgenic plants exhibited an increase of root length and fresh weight compared to those of WT. Moreover, in the presence of TCS, the activities of superoxide dismutase, peroxidase, catalase, and glutathione in transgenic plants were higher than those in WT. The concentration of TCS absorbed by T-S-C and T-S-P from the solid medium system increased by 50.0% and 24.1%, and from the hydroponics system increased by 55.6% and 38.0%, respectively, compared to those absorbed by WT. This study provides a proof of principle that transforming nanobodies into plants represents a novel technology to improve the efficiency of phytoremediation for environmental pollutants.