And the move, which follows a successful half-season loan spell, has sent the club off the ground ahead of the official summer transfer window opening tomorrow.
Targett, told by head coach Eddie Howe that the club wanted to sign him after the last game of the season against Burnley at Turf Moor, had signed for the club after taking a break in Ibiza with his partner.
The deal was simple as there was already a £15m deal with Aston Villa, the 26-year-old left-back’s parent club.
A Howe and a Targett had made their decision, it was a formality.
The question now is who will be the next player to travel to Newcastle.
United players return on July 1 and the club have a window to get things done.
The work on Targett was mostly done in January, and the club have already done a lot of work on another target – Sven Botman.
Botman was keen to join Newcastle in the last window, but the club could not agree a fee with Lille.
Talks have reportedly resumed over a £30m move for the 22-year-old, who is also a target for AC Milan.
“Talks are ongoing now,” Botman said earlier this month. “I’m not going to detail all of this, but it’s going well. I hope the transfer for the new season is completed. Preferably also for the pre-season.
“These clubs (Newcastle and Milan) are interested, yes. I can’t and I don’t want to say much more about it. What I want is to take a good step towards a great competition.”
There is optimism in St James’s Park that a deal for Botman can finally be agreed.
A move for Stade de Reims striker Hugo Ekitike – who was also a January target – is also on the cards.
Dwight Gayle, apparently in talks with Middlesbrough, will move on this summer, and Howe needs another player to compete with Callum Wilson and Chris Wood up front.
Ekitike, 19, did not want to leave his club in the last window, but he is available this summer. Reims president Jean-Pierre Caillot: “Hugo will be allowed to leave – and he will probably leave.”
The club’s market efforts will be led by new sporting director Dan Ashworth, who has had a series of meetings since joining the club earlier this week.
“We are about to start a transfer window so there will be a lot on the to-do list with players coming in and out, things that Eddie will want to do for the first team,” said Ashworth.
As Ashworth hinted, players also need to be moved on and Isaac Hayden has already joined Norwich City on loan. Others will follow him out of the club.
As for arrivals, Howe would like to see more before the start of pre-season training – and Botman could be the next to come through the doors.