The new £120m Seagrave site has been under construction since the spring of 2019 by McLaren.
The 180-acre site features 21 playing surfaces, including 14 full-size pitches and a 499-seater, floodlit show pitch plus a private nine-hole golf course.
Leicester City Chairman Aiyawatt Srivaddhanaprabha said: “The Club has taken some enormous strides forward in the last 10 years. In terms of our long-term future, this is perhaps the biggest.
“A new training ground has been a dream many years in the making, so it is with great pride that we have been able to deliver this. Seagrave will be a pivotal part of the Club’s operation for generations to come.
“Of all the investments we have made in the Club, this has been our most significant. It is an investment in our players of today and our players of tomorrow, putting some of the very best facilities in the world at the heart of their everyday environment.
“It elevates the Club’s offering to its players and staff to an entirely new level and is a key component in making our progress of recent years sustainable.”