He replaces Timo Sieg, also managing director in Germany, who will leave the firm at the end of 2011.
Gallagher takes his role after having worked as president of Ketchum Pleon, overseeing operations in Europe, including the UK, France, Italy, Spain, the Netherlands and Belgium.
He said he ‘looks forward to continuing to work closely with the leadership in the region and to our continued success’.
Gallagher previously oversaw the group’s pre-merger European operations. Before that, he led Ketchum’s UK operations, where he grew that business to double its size.
Dirk Popp will continue in his role as CEO of Germany.
Ketchum and Pleon merged in Europe in 2009, in one of the public relations industry’s largest-ever mergers.