  Using archival X-ray data, we find that the catalog location of the X-ray
binary Scutum X-1 (Sct X-1) is incorrect, and that the correct location is that
of the X-ray source AX J183528-0737, which is 15' to the west. Our
identification is made on the basis of the 112-s pulse period for this object
detected in an XMM-Newton observation, as well as spatial coincidence between
AX J183528-0737 and previous X-ray observations. Based on the XMM-Newton data
and archival RXTE data, we confirm secular spin-down over 17 years with period
derivative Pdot~3.9e-9 s/s, but do not detect a previously reported X-ray iron
fluorescence line. We identify a bright (Ks=6.55), red (J-Ks=5.51), optical and
infrared counterpart to AX J183528-0737 from 2MASS, a number of mid-IR surveys,
and deep optical observations, which we use to constrain the extinction to and
distance of Sct X-1. From these data, as well as limited near-IR spectroscopy,
we conclude that Sct X-1 is most likely a binary system comprised of a
late-type giant or supergiant and a neutron star.
