The former Everton man has looked revitalised following his loan move to Villa Park and his added time intervention makes it five straight wins for Dean Smith.
Villa skipper Jack Grealish was at the heart of it for the hosts in the early exchanges as his fizzed free kick brought the best out of Kasper Schmeichel.
The Foxes did improve after the break, but without Jamie Vardy spearheading their attack, the Foxes were restricted to half chances as Youri Tielemens tested Emiliano Martinez.
Leicester lack of cutting edge meant the door remained open to Villa in the closing stages as Ollie Watkins and Matty Cash both tested Schmeichel.
But despite looking well placed to hang on for the draw Leicester were undone by a flash of magic from Barkley.
John McGinn’s clever ball found him in space outside the box and his rocket of an effort flew past Schmeichel.
FULL TIME AT THE KING POWER STADIUM IT’S LEICESTER CITY 0 ASTON VILLA 1