Mitchell, who has already been working with the company as a consultant, is replacing Nick Caine who previously flagged his intention to step down back in October.
"We are delighted that Lisa has accepted this role,” said Ed Winter, Fastjet chief executive. “Her experience of working in various African jurisdictions will be invaluable and we look forward to welcoming Lisa to the board,”
"We will be sorry to see Nick leave and thank him for his dedication and great contribution to Fastjet and wish him every success in his future career."
Mitchell’s appointment comes after Winter revealed last week that he would also be leaving the company, though he remains in place whilst the company seeks a replacement.
Fastjet, a growing African airline, in December added new routes to and from Kenya, and yesterday announced the start of flights between Johannesburg, South Africa, and Harare.