We report room temperature deposition of compact Si films onto 6061 Al alloy from aqueous solutions containing 10 mM HF and 20 mM Na2SiF6 in 80 wt % formic acid (HCO2H) by a combination of galvanic and electroless deposition. Deposition for 30 h. yields a 7-10 mu m thick, dark grey Si thin film that does not change color upon exposure to air. Elemental analysis demonstrates that the as-deposited film contains 2-3 atom % Al, 4-5 atom % Cu, and 92-94 atom % Si. We believe that this is the first report of aqueous, room temperature deposition of thick, compact Si films. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3605307] All rights reserved.