The 33-year-old was released by County at the end of June and has signed a one-year contract with the Championship club.
Reguero moved to Dingwall on a free last summer and made 16 appearances as Jim McIntyre’s side secured a ninth place finish.
The Spaniard will serve as back-up to current Hibs No 1, Mark Oxley, who recently agreed a two-year deal having spent last year on loan in Edinburgh from Hull City.
Reguero told the Press and Journal: “This is a great move for me. I’ve really enjoyed the last three years in Scotland and I’m very pleased with my move to Hibernian.
“The club face a big challenge next season and I’m looking forward of being part of our bid for promotion.”
Hibernian goalkeeping coach Alan Combe told the club website: “We are delighted that Antonio has agreed to join us for next season. He is an experienced keeper and will be put through his paces alongside Mark and the rest of the squad here in our pre-season training at La Manga.”
Reguero joins fellow new recruits James Keatings, Danny Carmichael and Martin Boyle in Alan Stubb’s squad for the new season.