
Jowett previously held the position of sales manager, pan-European sales. In her new role, she will report to Warren Burke, commercial director at Yahoo global sales.
Her role within the London-based sales team will include developing strategic client and agency relationships.
Burke said Jowett's appointment was due to her "knowledge, professionalism, commitment, sense of humour and people skills with agencies and clients".
In February, Carol Bartz, the recently appointed Yahoo global chief executive, unveiled a major reorganisation, combining the company's technology and product groups into one division.
Bartz began restructuring Yahoo within a month and a half of joining the business in January. She came from Autodesk, where she was executive chairman and replaced Jerry Yang who stepped down to his former role as chief Yahoo in November last year.