Disclosed are various embodiments for leveraging large language models (LLMs) and retrieval-augmented generation (RAG) for data standardization of clinical AI data. A query comprising a target dataset that needs to be standardized and a dataset dictionary can be obtained. Augmented data can be extracted from an external source. A prompt including the query and the augmented data can be generated and applied to a large language model configured to output a response to the query. The response can include the target dataset standardized according to a standard format.