It is hoped Calver will also help grow the Mothercare and Early Learning brands internationally in growing markets such as Africa and the Middle East.
Calver, who has also held high profile roles at Dell and Pepsi, replaces Ben Gordon who stepped down from the chief executive role in November.
Alan Parker, Mothercare chairman, says: “Simon Calver is a highly successful business leader with experience heading multinational consumer facing organisations.
“His e-commerce and brand expertise will enable Mothercare to accelerate its development as a multi-channel retailer in the UK and his international perspective will be invaluable to the continued rapid expansion of Mothercare and Early Learning Centre globally.”
The chain is currently struggling to compete not only with online retailers, but with supermarkets such as Morrisons which has branched out into baby and kidswear with its new chain Kiddicare.
Mothercare reported a 3% decline in like-for-like sales in the UK in the 13 weeks to 7 January.
Earlier this week Mothercare signed up Jools Oliver, wife of celebrity chef Jamie Oliver, to push a new children’s clothing and bedding collection.