Hugh Dancy stars as the eponymous Daniel Deronda, with Romola Garai as his soul mate Gwendolen Harleth. Though entranced with Daniel, Gwendolen is forced into an oppressive marriage to Henleigh Grandcourt (Hugh Bonneville), while Daniel finds a new life through his friendship with Mirah Lapidoth (Jodhi May)

Daniel first becomes enchanted by the beautiful Gwendolen as she gambles recklessly at the roulette table. Her family have recently fallen on hard times and pinned their hopes upon the proud, but charming Gwendolen attracting a rich husband. A short while ago, Gwendolen reluctantly succumbed to the advances of rich bachelor, Henleigh Grandcourt, only to discover that he had a mistress, Lydia Glasher (Greta Scacchi), and three children.

Danie's also been troubled. Illegitimate and haunted by doubts about his own identity, he is frustrated that his uncle and lifetime guardian, Sir Hugo Mallinger (Edward Fox), will tell him nothing about his real parents. Later, he saves a young Jewish singer Mirah Lapidoth from drowning herself in the Thames.

Eventually, Gwendolen' marries Grandcourt, but soon realises he's still seeing his mistress. She's is trapped in a marriage that is doomed before it has begun. However, she's left widowed when Grandcourt drowns in a sailing accident.

Meanwhile, Daniel embarks on a journey to find his true identity and Mirah's family. It takes him into London's Jewish community and Genoa, where he meets The Contessa (Barbara Hershey), a celebrated opera diva who holds the key to his past. It is not until he has returned home to London that the idealistic, young hero's journey of self-fulfillment reaches a powerful and dramatic conclusion.