Gillis was most recently chief executive of health and fitness business Esporta, until it was sold by Duke Street Capital in May.
Prior to that he was managing director of the managed pub division of Greene King. He has also held roles at Proctor & Gamble, Cadbury Beverages and Heinz.
Gillis' appointment follows a period of intense pressure on Blacks Leisure chairman David Bernstein. Although Bernstein was understood to have favoured appointing acting chief executive Keith Fleming to the position permanently, rebel shareholders including Sports Direct International and Principle Capital investment Trust, were firmly against his appointment and had threatened overrule the board if their views were not taken into account. Adrian Wright, the former chief executive of SRG and Moss Bros was also linked to the chief executive post.