Forest beat the Terriers 1-0 at Wembley to secure their long-awaited return to the Premier League.
It has not played a top-flight match since the 1998-1999 season, with its 23-year gap between Premier League seasons being the longest for any club.
Its success on Monday highlighted the astonishing turnaround inspired by Cooper, who took over the club in September when it was second from bottom in the Championship – only Derby County, which had been deducted 12 points early in the season, was below the two-time European champion.
🥳 After 23 years, former European champion @NFFC is back in English football's top flight, promoted to the @premierleague after beating @htafc 1-0 in a controversial @EFL #Championship play-off final, and look at the celebrations!!#EFL #EFLPlayOffs #StepUp pic.twitter.com/LfY7xiiRoR— beIN SPORTS (@beINSPORTS_AUS) May 29, 2022
But since then, Cooper has won 60 per cent of his 45 games in charge, the best win ratio of any Forest manager (minimum 15 matches) since the club joined the Football League in the 1982-1993 season.
In that time, Forest's 27 victories across all competitions is more than any other Championship club, and Cooper – who lost to Brentford with Swansea City in last season's play-offs – was fully aware of the gravity of securing promotion.
"It's relief and pride – this isn't about me, but it's changed my life, potentially anyway," Cooper told Sky Sports.
"My family are here, the players' families are here – this football club is about belonging to a city. It comes together on matchday. We've taken over Wembley today and are in the Premier League.
"This football club is built on positive eras from the past and we want to build on that. We are proud of that but at the same time we need to think, 'what if?'
"Can we get the Premier League? Can we play attractive football? What if we can develop young players? And that's what we've done showing an attitude and a commitment to not get beaten. We deserve this."
While Cooper will attract many of the plaudits for the undeniably brilliant job he has performed since September, he was quick to pay tribute to his players and the atmosphere they have helped to cultivate in the club.
"It's a glamorous world being a footballer and a manager but it's also a harsh and spiteful one," he continued.
"I just wanted the players to know I will be their biggest supporter and give them everything through thick and thin.
"It doesn't mean I'm soft with them or don't demand of them but everybody loves to be loved. That's what we've tried to do with the players."