The committee Friday approved Loy's nomination by unanimous consent, clearing it for floor action this weekend or early next week.
The White House announced in late October its intention to nominate Loy as deputy secretary after former Deputy Secretary Gordon England returned to his post as Navy secretary.
Loy, who currently oversees the Transportation Security Administration at the agency, would continue in that capacity until a successor is named at TSA.
"There's a seat at the helm that is empty, and I can think of no finer person to fill it than the nominee before us," committee Chairwoman Susan Collins, R-Maine, said on Tuesday.
Homeland Security Committee Chairman Christopher Cox, R-Calif., said he looks forward to working with Loy, whom he called a "hands-on manager and a strategic thinker."