Featuring Entourage star Jeremy Piven, Zoe Tapper and Katherine Kelly, the show tells the story of Harry Gordon Selfridge, the founder of Selfridges department store.
The second series, which will once again be written by Andrew Davies and his team, will move the story forward to 1914 and the lead-up to World War 1.
Series one of Mr Selfridge is currently midway through its run and has been edging out BBC One's rival period drama Ripper Street in the ratings. However, it hasn't quite matched the figures of BBC One's Call The Midwife.
It is ITV's most-watched new drama since Scott and Bailey launched in 2011.
Steve November, ITV's acting director of drama commissioning, said: "It is ITV drama at its best and we are looking forward to spending more time with the wonderful characters."
The director of episodes 5, 6 and 7 of series one,