The Edinburgh club clinched the Championship title with a 3-0 win at home to Queen of the South.
And Hibs continue their Scottish Cup defence with a semi-final against Aberdeen at Hampden next Saturday.
"The players can be very proud of what they have achieved, the cup win and now promotion, it's heady days for us," Lennon told BBC Scotland.
"We were favourites going into the league and, to be fair, they have lived up to the billing.
"We've got a semi-final to prepare for as well, and we want to be competitive in that one, defending the trophy."
Match report: Hibernian 3-0 Queen of the South
The title win, with three games to spare, brings to an end a three-year period in the second tier.
"Hopefully we won't be back here for quite a while," said Lennon, who took over from Alan Stubbs in June last year.
"I came in at a good time, off the back of the cup win," added the former Celtic and Bolton boss. "Stubbsy left us a really good foundation to build on."
Lennon, 45, won three league titles and two Scottish Cups when in charge at Celtic.
When asked how this achievement compared, he replied: "It's up there. I had some great days at Celtic - great scenes - and this is just as good.
"It's nice to have a promotion on the CV.
"It's a great feeling personally and you can see what it means to people like George Craig [director of football] and Leeann Dempster [chief executive].
"There's plenty of work still to be done but the players should enjoy themselves today.
"They were fantastic today; that's what they are capable of producing."
Long-serving full-back Lewis Stevenson played in the side that was relegated via the 2014 play-offs and missed out at the semi-final stage of the play-offs in the past two seasons.
"It's been a long three years and I'm just glad we are finally over the line," said the 29-year-old.
"I've been here through thick and thin and it's times like these that make it worthwhile.
"There were dark times when I thought we'd never get back and I'm just glad to be part of it.
"I know it's been a kind of sticky run recently but the boys have been amazing this season and we did it in style today."
Manager Neil Lennon is looking forward to a bright future with Hibernian after securing a return to the top flight.