  We present the United States Naval Observatory (USNO) Bright-Star Astrometric
Database (UBAD), a current-epoch high-accuracy astrometric catalog. The catalog
consists of 364 bright northern hemisphere stars, including all but five such
stars with either $V < 3.5$ or with $I < 3.2$ and $V < 6$, as well as a large
fraction of slightly fainter stars; 36 of the brightest catalog stars are not
included in Gaia Early Data Release 3 (EDR3). Observations were conducted with
the USNO, Flagstaff Station, Kaj Strand 61-inch Astrometric Reflector. Target
stars were imaged through a small 12.5-magnitude neutral-density spot, while
the remainder of the stars in the field of view were unattenuated. This allowed
for unsaturated images of the bright target stars to be calibrated directly
against much fainter reference stars from Gaia EDR3. The median position errors
are 1.9 mas in both right ascension and declination at the catalog epoch of
2017.0, with 90% of catalog stars having errors less than 2.6 mas; systematic
errors are 1 -- 3 mas. Combining UBAD observations with Hipparcos-2 positions
yields proper motions with median errors of 0.045 and 0.049 mas year$^{-1}$ in
right ascension and declination, respectively, with 90% of stars having errors
less than 0.1 mas year$^{-1}$; systematic errors are about 0.1 mas year$^{-1}$.
Single-frame accuracy for positions of the target stars is typically 5 -- 6
mas. Gaia EDR3 astrometry for these bright stars, which are heavily saturated
in the Gaia observations, is validated over the magnitude range $2 \lesssim G
\lesssim 6$.
