D. Rabinowitz, C. Baltay, N. Ellman, E. Hadjiyska, and S. Tourtellote, Yale University Center for Astronomy and Astrophysics; P. Nugent, Lawrence Berkeley Laboratory; J. Bloom, University of California at Berkeley; J. Parrent, Dartmouth College and Las Cumbres Observatory; and D. A. Howell, University of California at Santa Barbara and Las Cumbres Observatory, report the discovery of an apparent dwarf nova on CCD images taken on June 11.046 (when the variable was at magnitude R = 16.3) and June 11.063 UT (at R = 16.0), as part of the La Silla-QUEST (LSQ) transient survey conducted with Yale University's 160-megapixel QUEST camera on the 1.0-m Schmidt Telescope of the European Southern Observatory at La Silla, Chile (Rabinowitz et al. 2011, Ap.J. 732, 512). The source's position is R.A. = 16h53m18s.57, Decl. = -16o17'54’'.2 (equinox 2000.0). No source brighter than R = 20.0 is visible at this location in repeated LSQ observations taken during 2010 May 21-June 14, and during 2011 Mar. 15-June 4. A faint source is reported at this position in the Guide Star Catalog V2.3.2 (with B_j = 20.76). Followup LSQ observations taken during June 12-18 reveal a gradual brightness decrease by 1.3 mag, becoming undetectable on June 23.00 (to limiting R magnitude 21), then detectable again on June 25.013 (at R = 18.3) and June 25.059 (at R = 18.4). Simultaneous visible/J-band observations taken with ANDICAM on the 1.3-m SMARTS telescope at Cerro Tololo reveal V = 17.95 +/- 0.05 on June 17.63, V = 18.22 +/- 0.03 on June 17.69, and V = 21.4 +/- 0.4 on June 26.60, with B-V = -0.54 +/- 0.06, V-R = +0.96 +/- 0.05, V-I = +1.36 +/- 0.05, and V-J = +2.32 +/- 0.18 on June 17.63. A spectrum (range 0.350-0.966 nm) taken on June 26 with GMOS on the Gemini South telescope reveals strong H-alpha and H-beta emission lines, with H-alpha clearly double-peaked, indicating the presence of an accretion disk with rotational velocity 1000 km/s. Additional outbursts of this source are likely, and future monitoring is encouraged.