Ingram, 68, has been added as a non-executive director.
He held the position at Zimbabwe-focused Caledonia for eight years before retiring in June 2010, and also been chief executive of a bank in the Democratic Republic of Congo.
The news comes as fastjet readies for the launch of the Zambia and Zimbabwe operations, expected in mid-November and early December respectively.
He is currently chairman of Greencoat UK Wind (LON:UKW), the European subsidiaries of QBE Insurance Group and of the Wealth Management Association.
Ingram represents easyGroup Holdings which holds a 9.9% stake in the company.