Wagner’s side created history as the 49th club to be inducted into the Premier League - 45 years on from their last appearance in the top flight.
The German head coach, who is attracting attention from other clubs both at home and abroad, said: “I think what has happened here normally would take three or four years, so to do what we have done is credit to everyone who has been involved.
“Especially the chairman. He always trusted me and showed belief in what we were trying to do.
“To all the backroom staff and players, too, and every single employee who works in the club.
“Finally I am so happy for the supporters. I know what a life-changing moment this is for all of them; it is amazing to say that Huddersfield Town are in the Premier League.”
There was no thought about promotion for Wagner’s men at the start of the season, no Town fan dared to dream of what has become a reality.
However, there were many who predicted Town would get relegated.
Wagner continued: “No, not at the start of the season, I didn’t see this coming.
“Of course, at the start of it, we were favourites to go down. I know a lot of the pundits wrote us off before the start of the season.
“I was sure in pre-season that we were not going to be in a relegation battle, that wasn’t going to happen.
“Over the course of the campaign I kept thinking we can do a little bit more, then when it came to around Christmas time and we had played everyone once I thought we had a real chance to get into the Play-Offs.
“What has happened now is a fairytale, a brilliant story, and I believe this group of players deserve this moment and to go up.”
Wagner arrived in West Yorkshire from Borussia Dortmund’s second team in November 2015, when the club had been in the SkyBet Championship for three years but had stagnated somewhat.
On coming to England and Town, Wagner said: “I thought it was a chance, a chance for me to show something outside of Germany.
“I can’t say I waited for this opportunity, this opportunity just came at me from around the corner.
“When I arrived I thought there was a lot of work to do at this football club, In my opinion we left no stone unturned, we tried a lot of things, using small details to help this club move forward.
“I am so happy because when I arrived in England everyone kept talking about experience, but in our case we had little experience, particularly for the German players, to play all those games with no winter break.
“We always had to fight against no experience with this group. I think experience can be important but that isn’t everything, as long as you have heart and desire then you can win.”
At the start of this season Wagner took the players away to Sweden, they camped under the stars on a remote island and, as well as cooking food around a camp fire, they were told they couldn’t use their mobile phones.
They were also told that the season to come had ‘no limits’.
Wagner said: “We started the season by saying ‘no limits’ and now we know where our limit is, and that is the Premier League.
“I think we made a lot of correct decisions, for instance one was that I said to the Chairman I want to keep our best players, and we did that. We then went out and added some good players with good characters to the group.
“We played well over the season, especially away from home, and even if we didn’t win we had a lot of comments from the opposition saying that we were one of the best teams they had played all season.
“The consistency from this team all season is one of the most important things for me.
“We were only one day not in the top six, so for me from 46 games we were 45 times in the top six, and this is just one detail which has helped us and made us go up to the Premier League.”
On the final itself – the game at Wembley ended in a 0-0 draw after extra time, Town winning 4-3 on penalties – Wagner said Town set up deep.
Town have now won three play-off finals in penalty shoot-outs and the head coach said: “We changed our idea a little bit, because Reading are so strong in ball possession it makes no sense to press too high, they are so strong on the ball they then can break on you.
“If you sit a little bit deeper, they still have a lot of possession but don’t do a lot with it. We took this plan and put it out there on the pitch.
“We couldn’t press them all the time, but when we did, it worked, we had some great opportunities which we couldn’t take, however to win it on a penalty shoot-out just makes it even better and bigger.”
“I was as confident as could be, there were three other great teams battling it out, and there were only small margins separating them. We knew we could do it because we were playing with freedom, there was no pressure on us.
“We respected all three teams in the play-offs, but if you win the semis then the final, you like it, but it is hard, so my thoughts are with the other three teams that were involved.
“They all did brilliantly over the whole season, but only one team can win and go up to the Premier League.”
For the record, Town have been involved in six penalty shoot-outs in the play-offs and they have won them all. No other club has won more than one!