The fact that we have got this sorted out so quickly shows how keen Gary is to join us
Northampton chairman David Cardoza
"It is a sign of our ambition that not only did we target Gary, but that we have been able to appoint him as our new manager.
"He has all the attributes we are looking for - experience, a proven record, he has led sides to promotion at different levels in the Football League and he has a wealth of experience and contacts.
"I met Gary on Thursday, we chatted again on Friday morning and agreed terms.
"The fact that we have got this sorted out so quickly shows how keen Gary is to join us and to be a success for us.
"I am sure the supporters are delighted with this and I hope they turn up in numbers to welcome Gary to Sixfields when we play Shrewsbury Town on Saturday afternoon."
Johnson's managerial career started with spells at Newmarket Town, Cambridge United and Kettering Town.
He took on the role of Latvia national team manager for two years in 1999 before returning to England to lead Yeovil.
In his four years with the Glovers he won the FA Trophy and took the club from the Conference to League One.
And that success continued when he joined Bristol City in 2005, taking them from League One to the 2008 Championship play-off final, which they lost to Hull.
He left the Robins in March 2010 by mutual consent, taking charge at Peterborough a month later.
Despite keeping them among the League One play-off contenders and winning 15 of his 33 games in charge, his relationship with Posh chairman Darragh MacAnthony broke down and he left London Road in January.
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