Sanchez has joined on a four-year contract and the deal will be rubber-stamped once international clearance is granted. The 28-year-old, whose tough tackling has earned him the nickname of 'The Rock', impressed for Colombia at the FIFA World Cup™ in Brazil.
Villa boss Paul Lambert said: "Carlos is a very experienced professional who played a prominent role in a Colombian team which captured everyone's imagination at this summer's World Cup in Brazil. He's a great coup for Villa.
"He does the simple things really well and he's excellent at spotting the danger, dealing with it and keeping it simple. His physical strength, too, is something we will benefit from in the middle of the pitch and his role will be a really important one for the team.
"We've beaten other teams to bring him here to Villa and I'm delighted as we needed someone of his ilk."
Sanchez, who played for Valenciennes in France for six years before moving to Elche last year, added: "I'm delighted to be here, it's something I have always dreamed of.
"It is very important for me to be here at Aston Villa, not only for me but for my family as well."