The Defensive Midfielder has been unattached since he departed with the Turkish Super Lig side Trabzonspor on mutual consent in March 2020 following the outbreak of Coronavirus.
Mikel, who won a host of domestic and European honours during a glittering 11-year stay at Chelsea, returns to English football
Manager Michael O’Neill said: “We’re delighted to bring John to the Club. His playing career speaks for itself and underlines his calibre as a player.
“I was really impressed with him when we met for the first time and he outlined what he wants from the next phase of his career.”
“We spent four hours talking and he made it clear he wants to get back into the Premier League and finish his career there and hopefully he can do that with Stoke City.”
Mikel made more than 370 appearances for Chelsea, helping them to land the Premier League title twice, as well as three FA Cups, the Champions League and Europa League.
After a spell in China, he played for Middlesbrough after joining them on a short-term deal in January 2019, making 19 appearances.
He won 91 caps playing at the FIFA World Cup, the Confederation Cup with winning the AFCON Cup in 2013, and bronze medals at the continent, before retiring from international football following last year’s African Cup of Nations.