Late embryogenesis abundant (LEA) proteins play an important role in plant growth and development, as well as in the plant response to various abiotic stresses. In this study, CsLEA1, a novel gene encoding a LEA_3 subfamily protein, was successfully cloned from a tea plant [Camellia sinensis (L.) O. Kuntze]. Bioinformatics analysis and prokaryotic expression assays showed that CsLEA1 is a typical hydrophilic protein with a molecular weight of approximately 10.4 kD. Expression analyses revealed that the transcription of CsLEA1 in C. sinensis leaves was significantly induced by cold stress. In addition, the heterologous expression of CsLEA1 increased the tolerance of Escherichia coli and yeast to cold stress, which might be closely related to the low molecular weight and high hydrophilicity of the CsLEA1. Taken together, our results suggest that CsLEA1 might have an important function in the tolerance of C. sinensis to cold stress, thus providing a potential application in molecular breeding to enhance the cold stress tolerance of tea plants.