Krained will initially lead Seatwave in Germany and the Netherlands but the company is set to expand in the region according to founder and chief executive Joe Cohen.
Cohen said: "Karl is the right person to push Seatwave's expansion, combining great leadership skills and brand development know how as well as online experience.
"With him at the top, Seatwave is set to strengthen its market position in Germany and to expand its presence further in Northern Europe."
The UK is a separate territory headed by managing director Richard Hurd-Wood, who recently joined from Camelot.
At Google Krainer was the marketing director for Germany, Austria, Switzerland and Scandinavia.
Before joining Google he was director of brand marketing at eBay and oversaw campaigns including '3 ... 2 ... 1 ... Meins'.