Harte, 34, previously played in the Premier League for Leeds United, and reached the semi-finals of the Champions League with the Yorkshire club in 2001.
The Irishman dropped down to League One with Carlisle United in 2009, before moving to Reading in 2010.
"It's pretty special, considering just over two years ago I was in League One, but I'm going back to the Premiership so I'm absolutely chuffed. There's a great bunch of lads here and great togetherness and we want to win the league," Harte told Sky Sports News.
"We didn't play well tonight but we had to dig out the result... come Saturday hopefully we can get three points again."