River Island saw profits jump by almost 70 per cent last year, boosted by the rise in mobile shopping and recent collaborations with popular celebrities such as Rihanna.
The fashion chain, which is privately owned by the Lewis family, reported pre-tax profits of £149.1m in 2014 compared with £88m the previous year.
Sales increased by 10.4 per cent to £925.8m, accounts filed last week on Companies House show.
River Island invested heavily in recent years in improving its IT systems and opening new stores, which has helped boost sales.
The retailer also made its first foray into the childrenswear market in a bid to broaden its appeal after launching a babywear range called River Island Mini in April last year.
Accounts show that the company paid a £100m dividend. However this is understood to have been reinvested in the firm.