She will bring more than 15 years of industry experience to the role when she takes up the mantle on 15 February.
De Hertogh – who will report to managing director international sales Marcel Fuchs – will be responsible for spearheading United’s overall sales strategy in the UK and Ireland.
"With over 15 years’ experience in the aviation business, Karolien has been at the forefront of change and brings great strength and expertise to our team as we build on our success in the UK and Ireland," said Fuchs.
"The whole United family wishes Bob Schumacher the very best after a highly successful career at United spanning almost 30 years."
Having originally joined United in 2007 as regional sales manager for the UK, Ireland and Belgium, De Hertogh was subsequently appointed as head of UK corporate sales.
Her appointment comes as the airline prepares to introduce an additional second daily flight between Heathrow and Los Angeles on 26 March.
