Hanrahan joins from consumer website Salary.com, where she also held the title of chief marketing officer. She has previously occupied marketing roles at Terra Lycos, General Mills and Lindt Chocolates.
The appointment is part of wider management changes at Cheapflights, which has also seen Francesca Ecsery promoted from UK general manager to global sales director.
In February, Cheapflights hired VCCP Search to its global paid search account following a three-way pitch.