Goalkeeper Liam Roberts and central defenders Fraser Horsfall and Jon Guthrie are the trio who have made the XI which is voted for by their fellow professionals.
Their selection is recognition for the Cobblers' excellent defensive record throughout last season, where they conceded just 38 goals in their 46 matches, keeping 21 clean sheets in the process.
The next best defence was Exeter City’s, who conceded 41.
Jon Brady's men missed out on promotion on a heartbreaking final day of the season where they were pipped to the post on goals scored by Bristol Rovers, before being beaten in the play-offs by Mansfield Town.
There are no Rovers players in the line-up, which also features five of Forest Green Rovers' title-winning side as well as Peter Clarke from Tranmere Rovers, Matt Jay from Exeter, who finished the table in second place, and Newport County striker Dom Telford.
The Forest green players selected are defender Kane Wilson, midfielders Nicky Cadden and Ebou Adams and forwrds Matt Stevens and Jamille Matt.
The Cobblers will now be hoping for good news from Horsfall and Roberts who have both been offered new contracts to stay at the club.
Guthrie still has a year left to run on the two-year deal he signed last summer.
The summer transfer window in England opens today (June 10).