As an indicator of the antioxidant capability of plants, catalase can detoxify reactive oxygen species (ROS) generated by environmental stresses. Sweet potato is one of the top six most important crops in the world. However, its catalases remain largely unknown. In this study, a catalase encoding gene,IbCAT2(accession number: KY615708), was identified and cloned from sweet potato cv. Xushu 18. It contained a 1479 nucleotides’ open reading frame (ORF). S-R-L, Q-K-L, and a putative calmodulin binding domain were located at the C-terminus of IbCAT2, which suggests that IbCAT2 could be a peroxisomal catalase. Next-generation sequencing (NGS) based quantitative analyses showed thatIbCAT2was mainly expressed in young leaves and expanding tuberous roots under normal conditions. When exposed to 10% PEG6000 or 200 mmol/L NaCl solutions,IbCAT2was upregulated rapidly in the first 11 days and then downregulated, although different tissues showed different degree of change. Overexpression ofIbCAT2conferred salt and drought tolerance inEscherichia coliandSaccharomyces cerevisiae. The positive response ofIbCAT2to abiotic stresses suggested thatIbCAT2might play an important role in stress responses.