Twohill joins next week as a consultant and will be based at the company's London office, which is led by head of UK operations Kate Burns. She resigned her post as head of market development at online travel retailer Opodo in April, coinciding with the arrival of commercial director Karen Richardson.
Her role at Google will comprise both marketing its search listings services to business customers and overseeing the launch of other services aimed at consumers.
Products in the pipeline include an automated telephony service, Google Voice Search, a dictionary service, Google Glossary, and a quote-tracking engine, Google Webquote.
It recently launched Google News, offering breaking stories amassed from 4500 sources, as well as photograph indexing. In the US it also operates a product search site called Froogle.com.