The Habitable Worlds Observatory Preliminary Input Catalog (HPIC) is a list of approximately 13,000 nearby bright stars that could serve as targets for the Habitable Worlds Observatory (HWO) in its search for Earth-sized planets around Sun-like stars. The HPIC was constructed using data from the TESS and Gaia DR3 catalogs, and an automated pipeline was developed to compile stellar measurements and derived astrophysical properties. The stellar properties in the HPIC were benchmarked against those of the manually curated ExEP HWO Precursor Science Stars list, and found to be consistent for the 164 best targets for exo-Earth direct imaging. The HPIC was demonstrated to be useful for predicting the science output of various mission designs, including those with larger telescope diameters and those focused on other planet types besides Earth analogs. The breadth and completeness of the HPIC are essential for accurate HWO mission trade studies and will be useful for other exoplanet studies and general astrophysics research on the population of bright nearby stars. The HPIC was constructed by selecting stars within 50 pc and with apparent magnitudes less than 12. This ensures that the catalog is volume complete and includes stars that are bright enough for direct imaging. The catalog was built using a pipeline that automates the selection and characterization of stars, allowing for simple updates as new data becomes available. The pipeline includes steps for gathering stellar properties, such as positions, photometry, binarity, distances, effective temperatures, luminosity, radius, metallicity, mass, age, and surface gravity. The catalog is designed to be agnostic of mission design and is intended to be a preliminary input catalog for HWO. It is expected to be useful for other upcoming great observatories as well. The HPIC is designed to be complete and accurate, with a high catalog completeness for most astrophysical properties, and is consistent with the ExEP HWO Precursor Science Stars list, with only a few outliers. The catalog is expected to be useful for exoplanet yield calculations and other studies of bright nearby stars.The Habitable Worlds Observatory Preliminary Input Catalog (HPIC) is a list of approximately 13,000 nearby bright stars that could serve as targets for the Habitable Worlds Observatory (HWO) in its search for Earth-sized planets around Sun-like stars. The HPIC was constructed using data from the TESS and Gaia DR3 catalogs, and an automated pipeline was developed to compile stellar measurements and derived astrophysical properties. The stellar properties in the HPIC were benchmarked against those of the manually curated ExEP HWO Precursor Science Stars list, and found to be consistent for the 164 best targets for exo-Earth direct imaging. The HPIC was demonstrated to be useful for predicting the science output of various mission designs, including those with larger telescope diameters and those focused on other planet types besides Earth analogs. The breadth and completeness of the HPIC are essential for accurate HWO mission trade studies and will be useful for other exoplanet studies and general astrophysics research on the population of bright nearby stars. The HPIC was constructed by selecting stars within 50 pc and with apparent magnitudes less than 12. This ensures that the catalog is volume complete and includes stars that are bright enough for direct imaging. The catalog was built using a pipeline that automates the selection and characterization of stars, allowing for simple updates as new data becomes available. The pipeline includes steps for gathering stellar properties, such as positions, photometry, binarity, distances, effective temperatures, luminosity, radius, metallicity, mass, age, and surface gravity. The catalog is designed to be agnostic of mission design and is intended to be a preliminary input catalog for HWO. It is expected to be useful for other upcoming great observatories as well. The HPIC is designed to be complete and accurate, with a high catalog completeness for most astrophysical properties, and is consistent with the ExEP HWO Precursor Science Stars list, with only a few outliers. The catalog is expected to be useful for exoplanet yield calculations and other studies of bright nearby stars.