It was a frustrating day at the King Power Stadium for the Black Cats, who were without playmaker Stephane Sessegnon.
There were few chances in the first half and the home side had the better of the play.
Both Jermaine Beckford and Ben Marshall forced good saves from Sunderland goalkeeper Keirin Westwood before the break.
Sunderland started better in the second period as James McClean got into the game more.
It was Leicester who edged ahead though through substitute Parkes, when he poked the ball home following a corner.
Sunderland thought they had equalised but McClean's header was adjudged not to have crossed the line.
The visitors pushed for a goal late on but it was an ultimately disappointing return to Leicester for Martin O'Neill.
Sunderland face a tough trip to Arsenal when the Premier League gets underway next Saturday.