The company, which targets older and larger shoppers with brands such as Simply Be and Jacamo, said Spindler will join the firm before July to ensure a smooth succession.
White will retire after 25 years and plans to build a portfolio of non-executive directorships.
Spindler headed the Original Factory shop since 2009, where she has led the value retailer’s fast-growing expansion.
She kicked-off her career at Coca-Cola, before spending ten years in a number of marketing and sales roles at Pedigree Masterfoods. In 1997, she joined Asda, eventually becoming global managing director of its £2bn clothing label George in 2005.
She left in 2007 to take up the role of managing director at department store group Debenhams.
N Brown chairman Andrew Higginson said Spindler “has the personal qualities to lead the team, and the business, as it continues its growth online and internationally.”
Shares rose 2.3 per cent yesterday on the announcement.