Set in the late 1820s and 1830s, after the Napoleonic Wars, the novel spans a period of 10 to 15 years and details the life of Maggie Tulliver, and her brother Tom, growing up at Dorlcote Mill on the River Floss at its junction with the more minor River Ripple near the village of St Ogg's in Lincolnshire, England.

The story begins when Maggie is 9 years old, 13 years into her parents' marriage.

Main focus of the story is on her relationship with her older brother Tom, and her romantic relationships with Philip Wakem (a hunchbacked, sensitive and intellectual friend) and with Stephen Guest (a vivacious young socialite in St Ogg's and assumed fiance of Maggie's cousin Lucy Deane) constitute the most significant narrative threads.