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The UV contains unique constraints on the atmospheric properties of a planet. Yet comma the UV is an often overlooked wavelength region for exoplanet studies despite the wealth of information it contains on aerosol scattering properties and V1.0 absorbers. We propose to conduct a Hubble Ultraviolet-optical Survey of Transiting Legacy Exoplanets (HUSTLE) treasury program using the newly proven capabilities of the WFC3-UVIS G280 grism to produce a spectroscopic survey of 14 exoplanet atmospheres from 200-800nm. G280 has the highest throughput among all Hubble.s UV instruments comma making it an important instrument for the future of UV exoplanet science. This program targets giant planets from warm Neptunes to ultra hot Jupiters with equilibrium temperatures from 900-2600K comma spanning a broad range of chemical comma aerosol comma and irradiation conditions. This treasury program will expand Hubble.s UV legacy for exoplanet studies comma and in doing so comma will address several important science questionsdoublePoint 1) place constraints on aerosol particle sizes comma altitudes comma and vertical mixing of clouds on the planetary limb comma 2) identify and constrain the abundance of any Mid to Near-UV absorbers comma and 3) leverage these directly measured properties to create legacy datasets to facilitate comparative studies comma adding to our understanding of the mechanisms that sculpt these worlds. Our target list includes a number of well known exoplanets that have formed the basis of our understanding of these extreme atmospheres and are already targets for Webb. The HUSTLE treasury program will provide the critical missing puzzle pieces to ensure that we can view the full picture of exoplanet atmospheres now and in the future.