The Reds end the season in an impressive 14th place despite defeat on the final day.
Barnsley ended the season with a battling performance, but ultimately slipped to a 3-0 defeat against newly crowned champions Newcastle United.
The result means the Reds conclude an excellent season in 14th place in the Championship table, a fantastic achievement from Paul Heckingbottom's side.
A team that some had written off at the start of the season as relegation candidates, the Reds have surpassed all expectations and finished in a respectable mid-table position, overcoming every obstacle that has been put in their way and turning plenty of heads in the process.
Despite carving out the early openings with Tom Bradshaw and Josh Scowen going close, the visitors were hit by a fast break, from which Christian Atsu squared for Ayoze Perez to fire home.
The Magpies doubled the lead just before the hour as Perez’s fierce drive was parried away expertly by Adam Davies, only for the loose ball to drop to the feet of Chancel Mbemba who slotted the rebound home.
Had it not been for a stunning save from Davies, Aleksandr Mitrovic would have made it three, but he tipped his header away from close range, with Jonjo Shelvey striking the post soon after.
Substitute Marley Watkins almost pulled a goal back with his close range header smartly saved by Rob Elliot, with fellow replacement Elliot Lee going close with a driven effort that Elliot again saved well.
The Reds’ efforts proved in vain and just as substitute Dwight Gayle tucked home Mitrovic’s headed pass, the moment Jack Grealish levelled for Aston Villa against Brighton, confirming the Magpies as Champions.
Neither side could create a clear opening in the early exchanges with a snap shot that drifted wide of Rob Elliot’s near post, with a low Josh Scowen drive midway through the half bringing the first save out of the Newcastle stopper.
Almost immediately after that chance, the Magpies took the lead as Christian Atsu centred and with the ball behind him, a deft flick from Ayoze Perez beat Adam Davies from six yards out.
But for a flying save from Davies it would have been two goals in a matter of minutes for the hosts, Atsu cutting inside again and firing towards the top corner, only to be denied by the Welshman.
Just before the break, Atsu unleashed another low drive that went fizzing towards the bottom corner, but once again, Davies was on hand to turn the ball away to safety.
On the stroke of half time, Massadio Haidara charged into the area to get on the end of another low ball from the right, blazing well over the top with most of the goal to aim at.
HALF TIME: Newcastle United 1-0 Barnsley.
The Magpies started the second half the better of the two sides with Perez firing straight at Davies from just outside the area, following that chance up with a couple of corners, both of which were cleared.
Moments before the hour mark, Davies made an outstanding one-handed save to deny Perez from a tight angle, however the loose ball fell perfectly for Chancel Mbemba, who ran onto the effort and steered it home.
The Reds were indebted to Davies once again on 68 minutes as Jonjo Shelvey’s corner was firmly met by the head of Aleksandr Mitrovic, only for a strong hand from the Reds ‘keeper to push an almost certain goal over the top.
Shelvey almost scored with his final touch of the match four minutes later, driving from the heart of midfield and taking aim, only to strike the outside of the post with his low effort from just outside the area.
The Reds came close to pulling a goal back when Scowen’s centre was headed goalward by Watkins but Elliot spread himself well to save, with the follow-up from Elliot Lee deflected behind.
Lee came even closer four minutes from time as his left-footed shot from the edge of the area forced Elliot into another good save, this time with his feet.
In the final minute, substitute Dwight Gayle nipped in to poke home Mitrovic’s header and put the result beyond all doubt, securing the Magpies the Championship title in the process as Brighton slipped up late on against Aston Villa.
Newcastle United: Elliot (GK), Yedlin, Mbemba, Hayden (Haidara, 13’ ), Dummett, Colback, Shelvey (c) (Diame, 72’ ), Gouffran, Perez (Gayle, 80’ ), Atsu, Mitrovic.
Subs: Darlow (GK), Lazaar, Anita, Murphy.
Barnsley: Davies (GK), Janko, A. Jackson, MacDonald, Elder, Hedges (Watkins, 54’ ), Scowen (c), James, Moncur, Kent (Williams, 74’ ), Bradshaw (Lee, 74’ ).
Subs: Townsend (GK), Evans, Mowatt, Jones.
Attendance: 52,276 (2,700+ away)