The CRITICAL dataset is the first cross-Clinical and Translational Science Award (CTSA) initiative to create a multi-site, multi-modal, de-identified clinical dataset. It combines deep-data depth with broad-data width, addressing a major unmet need in healthcare research. The dataset encompasses comprehensive longitudinal inpatient and outpatient data, including pre-, during- and post-ICU admissions, for approximately 400,000 distinct critical-care patients. This diverse dataset supports the exploration of urgent clinical problems and facilitates the development of fair and generalizable AI tools for advanced patient monitoring and decision support. The dataset has been curated to serve the research community, fostering innovations in AI/machine learning (ML), outcomes research, and other translational science domains. Its unique combination of size, diversity, and comprehensiveness makes it a valuable resource for tackling long-standing clinical challenges. The metadata provided here for this dataset is licensed under Attribution 4.0 International (CC BY 4.0). Please note that access to the data itself is restricted and requires compliance with the applicable Data Use Agreement (DUA). More information about the DUA and how to request access can be found at https://critical.fsm.northwestern.edu/, or by contacting critical@northwestern.edu.