Fans' favourite Hassell will start his 10th season at Oakwell after signing a new 12-month contract, while Cranie has put pen to paper on a new two-year deal, as has keeper Steele.
Tykes manager David Flitcroft told the club's official website: "It's great to have Bobby on board.
"It took longer than it should of to get completed for a couple of reasons. The change at chief executive level and a situation where Bobby wanted to look after his wife and new-born child, which tells you everything about Bobby as a character.
"From a footballing perspective we have retained an experienced Championship player with pedigree and know-how. That experience will prove vital in strategic points of the season and in games.
"There's a feelgood factor around the club to the loyalty Bobby has shown. The fans love him, the club loves him and with Bobby signing the feeling seems to be mutual."
Flitcroft feels Cranie is also another crucial signing for the club, who have also signed winger Dale Jennings following his release from Bayern Munich and striker Chris O'Grady from Sheffield Wednesday.
"The signing of Cranes is another piece of business I am delighted with," Flitcroft added. "I spoke to him and his agent that much, I might as well have gone on holiday with the two of them.
"Cranes' form last season was outstanding. He got better and better with each game and his level of consistency impressed me.
"When you see a player on that curve you have to sign them or it's a year developing someone that's wasted and then you have to start again. We had to fight off other potential suitors that Cranes' form alerted."
Flitcroft said earlier this month that he was reluctant to offer the 28-year-old Steele anything longer than a one-year deal, but he will now stay with Barnsley until the summer of 2015.
Steele told the club's offical website: "These things take time to get sorted, but now it's done I'm over the moon and I'm very happy to have a new two-year deal.
"I'm excited about this project and I like the whole plan that the club has to move forward. It's the most exciting contract I've signed in my time at the club.
"Seeing the signings of all the players that did so well last season was important to me. It gives real stability. Often at the end of a season I have been used to a lot of players going out and new ones coming in, but this year it hasn't been the case.
"I think it's very important to get that level of consistency which we have now. It feels like we can carry on where we left off from last season.
"I didn't ever see myself leaving although other clubs were interested. There is only one club that I support and that is Barnsley."
Steele, who started out at Peterborough and sealed a £500,000 switch to Manchester United in 2002 at the age of 17, spent two years at West Brom before joining Barnsley after an initial loan spell in May 2008. He has made nearly 200 first-team appearances for the Tykes.