She will oversee a £60m annual marketing budget and brands including Andrex toilet tissue, Kleenex tissues and Huggies babycare products.
Underhill previously headed up Kimberly-Clark's North American Group Brands, where she was responsible for tissue brands including Kleenex, Scott and Viva.
In her new role she will report to Giles Turrell, president of consumer Europe.
She replaces Troy Warfield who has been promoted to the new position of vice-president, family care, for Europe.
Warfield is now responsible for strategy, insight, communication and innovation across Kimberly-Clark's European Family Care business. He continues to be based in the UK.
Earlier this year, Warfield was ranked 16th in Marketing's Power 100 2009 listing of the industry's most influential practitioners.