Edwards, who last player for the Windies in 2012, has been signed on a Kolpak contract, so will not count as an overseas player.
He will arrive on July 27 ahead of the start of the Royal London One-day competition and will be available for all formats.
The 33-year-old told the club???s website: “I’m delighted to have signed for such an ambitious club as Hampshire. I hope I can play a part in helping to bring success to the Ageas Bowl this year.
“I’m very much looking forward to my first taste of county cricket. It’s also an honour to follow other Bajans like Malcolm Marshall and Gordon Greenidge to Hampshire.”
Edwards played in 55 Tests for the West Indies and 50 One-day internationals.
In March, he took the extraordinary figures of 8-40 against Nottinghamshire in a T20 friendly in the Caribbean.
Hampshire director of cricket, Giles White said: ???Fidel is a good option for us. He arrives ahead of the Royal London One-Day Cup and should give our attack variety which we feel is key in the 50-over format.??
???His stay will also extend to Championship cricket and he will be available until the end of the season.?????