Ajax Amsterdam announced its contract with the former Liverpool captain, just six months after his transfer to the Saudi agreement failed.
The Dutch club had confirmed that a two-and-a-half-year contract had been agreed with the English star.
Henderson had left Liverpool to join former Reds legend Steven Gerrard in the Saudi Al-Ettifaq team. But the adventure did not go as planned, and the decision to leave the club is said to have cost Henderson a fortune, especially since he did not receive any payment from his £350,000-a-week contract.
33-year-old Henderson, who will wear the number 6 shirt for Ajax, hopes to return to his best condition as soon as possible.