Based in Munich, she will be responsible for "the innovation of company communications, the further driving of the digitalization of communications channels and processes, and the further development of marketing and branding" in the global role, a company press release said.
Haller previously worked at Credit Suisse for nearly two years before leaving in November. She has also worked in Switzerland for manufacturer ABB and pharma firm Roche Diagnostics, both in senior comms roles.
However, she will not oversee the firm's government affairs unit, which is being transferred into the company's governance and markets department on 1 June.
"Early engagement with regulatory topics and so-called government-to-government business are of growing importance for the successful implementation of our company strategy. Siemens is taking account of this development and will intensively align its activities accordingly," said CEO Joe Kaeser.
Previous head of comms and government affairs Stephan Heimbach stood down from the role on 1 March, but it was not clear what role he would be heading to following his nine years in the post.
Siemens reported revenue of €75.6bn ($86.3bn, £59.8m) last year, and has around 348,000 employees worldwide.