The 28-year-old joins the Sons of Khabur after one season with the Buccaneers where he made 23 appearances across all competitions.
Mbule was part of a Bucs team led by Abdeslam Ouaddou that claimed a famous treble as they won the Betway Premiership, MTN8 and Carling Knockout Cup.
Zakho confirmed the player's arrival with a club statement, reading: "South African player Sipho Mbule has officially signed with our club for the 2026–2027 season in the Iraqi Stars Football League.
"Sipho Mbule stands out for his impressive speed and intelligence, with the ability to dictate the flow of the game at will and dominate the midfield.
"With Sipho’s arrival, our midfield will be stronger than ever."
Reflecting on the move, Mbule posted: "Thanks for the Year that was filled with happy moments than sad moments.
“TILL WE MEET AGAIN. To Orlando Pirates Fans, thanks for everything. FOR THE LOVE. FOR THE NOISE & THE BELIEF !!!!!”
