Gardner is part of a consortium of international and local businesses which has taken over the club - and is hoping to take Premier League football to Devon within the next five years.
Formerly the chief executive of Centrica, Gardner was at the helm at Old Trafford from 2003 until 2005, leaving the club following the takeover by Malcolm Glazer.
He has bought 13% of the shares in Argyle with long-term business associate Keith Todd as part of their KKC joint venture, with Japanese business Kagami Group owning a further 38%.
The group has confirmed that Paul Sturrock will remain as the club's manager, and Gardner believes he is the man to lead the club to a brighter future.
He said: "The priority next season is stabilisation and laying good foundations for the future. Paul Sturrock is the right man to do this on the football field and take the club forward.
"We are working with Paul to consolidate the squad in the pre-season. As we develop a better understanding of the club's precise needs, we plan to progressively increase the budget for new players, in particular as we grow the commercial income."
The new owners are currently working on a five-year business plan, and are planning to establish links with clubs and academies in both Japan and the USA.
Outgoing chairman Paul Stapleton will stay on the board as vice-chairman along with fellow directors Tony Wrathall and Robert Dennerly.
And Todd believes the club has the potential to be huge.
"There are great opportunities here," he said. "Plymouth's maritime and armed forces history gives the club huge potential.
"There are hundreds of thousands of people around the world with great affection for the town and the club. We will use new technology to build the fanbase and help deliver commercial success."