Translation naturalness refers to the quality of a translated text that closely resembles natural, fluent, and idiomatic usage in the target language, while maintaining the essence and intent of the original message. It goes beyond a word-for-word translation by considering the cultural nuances, idiomatic expressions, and stylistic conventions of the target language. This research discusses about the naturalness in the “The Midnight Library” novel by using Nida’s concept. The aim of this research is to find out naturalness words in the translation of “The Midnight Library” novel. The research adopts textual analysis method to investigate the research question in this research. The naturalness in “The Midnight Library” novel is analysed by using Nida’s concept of naturalness in translation (2000). In this research, the researcher found three phrases classified as the receptor language and culture as a whole, three pharases classified as the context of the particular message, and two phrases classified as the receptor language audience. Findings of this research present a crucial resource for future researches of naturalness translation studies