Former Southampton player Harrison holds UEFA A coaching badge, a minimum requirement for a coach in the CAF interclub.
The former Southampton and Stoke City player has been in Africa having coached 13 clubs Mark has coached mostly in Southern Africa where he handled Township Rollers of Botswana, Baroka FC, Chippa United and Golden Arrows of South Africa.
The Englishman, 60, jetted in last week and has been unveiled to fill up the gap left by Portuguese coach Manuel Vaz Pinto who parted ways with the club recently on mutual consent.
Harrison was at Camp Toyoyo on Saturday last week as Gor Mahia engaged AFC Leopards in a friendly game.
Sammy ‘Pamzo’ Omollo who has been handling the team since the departure of Vaz Pinto will remain as the assistant coach.
Harrison played for Southampton between 1977 and 1979, was at Stoke City between 1982 and 1984, and the two clubs are among eight sides he featured for during his active playing career.