This season has seen the Leicester-born player break through into the First Team ranks.BCFC
The 21-year-old defender's new contract will be effective from 1 July 2018 and runs until 30 June 2020.
This season has seen the Leicester-born player break through into the First Team ranks.
He made his debut as a substitute in the EFL Cup victory over Crawley Town, when he replaced Emilio Nsue just before the hour-mark in the 5-1 win.
His second appearance came two weeks later in the same competition, when once again he replaced Nsue as a substitute, during the 2-1 home defeat to Premier League side Bournemouth.
Harding, who can play at either centre-half or right full-back, is a product of Blues' Academy, which he joined at the age of 16.
After working his way through the age groups, he became a regular for the Club's Under-23s side, and is currently captain.
Harding has been named in the Blues Under-23s squad for tonight's Premier League Cup game against Middlesbrough at Nuneaton Town (7pm).
Josh Dacres-Cogley, Charlie Lakin, Corey O'Keeffe, Steve Seddon and Connal Trueman are also in the party for Blues' final group match of the competition.
Blues have an outside chance of qualifying for the knockout stage as one of the top two finishers in Group A. They need to beat Boro and hope Nottingham Forest come a cropper in their two remaining matches.