London, 1908. The bold retailer, Harry Selfridge (Jeremy Piven), is assembling his great plans for the biggest and finest department store the world has ever seen at the ‘dead Mr. Selfridge 47 end’ of Oxford Street. Facing a frosty reception from the anti-American press, Harry runs into unexpected trouble when his business partner Waring suddenly pulls out of the project, which leaves the life of the project hanging in the balance. But Harry’s luck is up when journalist Frank Edwards throws Harry a lifeline, offering to show new-to-town Harry around London and introduce him to the right people.

Selfridge’s has now been open for a few months. The displays are still as dazzling and seductive as on opening day, and the staff are ready and poised for action. The only thing the store is missing… is customers! Lady Mae (Katherine Kelly) stops by the Selfridge house to see how Rose Selfridge (Frances O'Connor) and the family are settling in. Slightly disapproving of the fun-loving and energetic Selfridge children, Lady Mae needles Rose about being an outsider to London Society and about Harry’s behaviour, and is shocked when Rose tells her she plans to visit the National Gallery, via the Underground!

Harry has a new idea: he wants to create a new Beauty Counter at the front of the store that sells perfume and even makeup – much to the consternation of some of his staff. Agnes runs into trouble with Reg, whilst Victor is still interested in her. Both Lois and Henri spot the threat of an ascendant Ellen Love, and Agnes helps Henri develop the new house perfume. Lady Mae asks Harry for a favour, and also reveals to Rose the truth about Ellen and Harry’s partnership - which spurs Rose to do something for herself.

Harry scores a massive coup when world-famous ballerina Anna Pavlova agrees to visit the store. Feeling coolness in Harry’s affections, a disgruntled Ellen leans on Frank for support. Reg’s violent tendencies reach breaking point when he crashes into the store at the worst of moments. Victor saves the day, and prevents George from getting into hot water in the loading bay. One of Harry’s closest employees is caught stealing, and a formidable new Head of Fashion arrives. Rose and Roddy’s friendship hits a surprising low when she reveals her true identity. Ellen is fired as the Spirit of Selfridges.

Harry is delighted with the motor car he has had brought in for a new window display. Roddy surprises Rose at home, where he is spotted by young Beatrice. Harry visits Agnes to persuade her to come back to the store.

Harry is unconscious after his car accident - and he suffers more flashbacks to a specific moment in his childhood. The Selfridge family are in disarray by Harry’s bedside. The store is gripped waiting for news when word arrives that Mrs Grove has died - big news for Miss Mardle. An impending Suffragette demonstration in the area forces the staff to pull together, and a grief-stricken Grove struggles to asks a confused Miss Mardle for some time apart. Whilst Victor and Lady Mae are having a secret affair, Agnes and Henri’s friendship grows.