  We present the Data Release 10 Quasar (DR10Q) catalog from the Baryon
Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III.
The catalog includes all BOSS objects that were targeted as quasar candidates
during the first 2.5 years of the survey and that are confirmed as quasars via
visual inspection of the spectra. The catalog also includes known quasars
(mostly from SDSS-I and II) that were reobserved by BOSS. The catalog contains
166,583 quasars (74,454 are new discoveries since SDSS-DR9) detected over 6,373
deg$^{2}$ with robust identification and redshift measured by a combination of
principal component eigenspectra. The number of quasars with $z>2.15$ (117,668)
is $\sim$5 times greater than the number of $z>2.15$ quasars known prior to
BOSS. Redshifts and FWHMs are provided for the strongest emission lines (CIV,
CIII, MgII). The catalog identifies 16,461 broad absorption line quasars and
gives their characteristics. For each object, the catalog presents five-band
(u, g, r, i, z) CCD-based photometry with typical accuracy of 0.03 mag and
information on the optical morphology and selection method. The catalog also
contains X-ray, ultraviolet, near-infrared, and radio emission properties of
the quasars, when available, from other large-area surveys. The calibrated
digital spectra cover the wavelength region 3,600-10,500\AA\ at a spectral
resolution in the range 1,300$<$R$<$2,500; the spectra can be retrieved from
the SDSS Catalog Archive Server. We also provide a supplemental list of an
additional 2,376 quasars that have been identified among the galaxy targets of
the SDSS-III/BOSS.
