A member of the African National Congress, Jack was appointed to the Northern Cape Provincial Legislature in June 2013.

Jack held the position until his appointment as MEC for Education in May 2019, despite him briefly being demoted from the Executive Council in May 2017.

McCollen Ntsikelelo Jack was born on 8 March 1965 in the town of Graaff-Reinet, then part of South Africa's Cape Province.

[10] Later on, he began working as the principal at the Lillian Noveve Combined School in Victoria West.

Newly elected premier Sylvia Lucas appointed him the Member of the Executive Council (MEC) for Transport, Safety and Liaison on 5 June, succeeding Patrick Mabilo.

Jack succeeded Mxolisa Sokatsha on 30 May, while Martha Bartlett became the new Transport, Safety and Liaison MEC.

[12] Lucas reshuffled her cabinet on 1 March 2016 and appointed him the MEC for Finance, Economic Development and Tourism, succeeding John Block.