The 28-year-old defender, who has previous top-flight experience with West Brom and Aston Villa, has joined the Tigers on a three-year deal, with the fee believed to be between £2million and £3million.
And Davies is relishing the chance to return to the top flight. He told the club's official website: "I'm delighted to be here.
"I feel that I'm joining Hull City at an exciting time and the chance to play in the Barclays Premier League was also a huge attraction.
"It's something that I've been lucky enough to do before and I wanted to get back to that level.
"Hopefully I can help this team to have a good season and push as high up the table as possible. I can't wait for Chelsea on the first day of the season now."
Davies is unlikely to be the last summer acquisition at the KC Stadium, with manager Bruce having a transfer budget of £10-£15million at his disposal. He is known to be particularly keen to add a goalkeeper and a centre-forward to his promotion squad.
Press Association Sport understands that Hull and Leicester have so far been unable to agree a fee for Kasper Schmeichel, leaving Bruce to run the rule over the likes of Allan McGregor, Ross Turnbull and Costel Pantilimon.
Celtic's Gary Hooper and Burnley's Charlie Austin are among the reported targets up front.