Described as having "a heart large enough for any six ordinary old gentlemen of humane disposition," Mr. Brownlow is a kind gentleman who inadvertently rescues Oliver Twist from the clutches of the heinous Fagin. In Chapter X, for instance, when the Artful Dodger picks the pocket of Mr Brownlow and darts away, the gentlemen reaches for his handerchief and realizing that it is gone, he tries to stop Oliver who has accompanied the other boys without realizing that they were going to steal. After "a great lubbery fellow" punches Oliver in the mouth, the boy falls, bleeding. A trip to the court helps neither Mr. Brownlow nor Oliver who is thrown into the street. However, the book-staller, who has accompanied Brownlow to court assists the old gentleman as he takes Oliver to his dwelling where his servant, Mrs. Bedwin, tends to him in his illness. Later, Mr. Brownlow buys Oliver some new clothes. But, when he sends Oliver to return some books for him after the boy is well, Oliver is recaptured by Nancy, and Mr. Grimwig, Browlow's friend, believes Oliver dishonest.
Having been recaptured for Fagin, Oliver is used in a robbery that goes badly; he is again injured, but the people in the house take kindly to him and call a doctor. The ladies, Mrs. Maylie and her adopted niece, Rose, tend Oliver and become endeared to him. After Oliver's broken arm heals, they take a trip to London where Oliver sees Mr. Brownlow and is reunited with him. Mr. Brownlow is elated to see Oliver again, his faith in the boy restored. Then, Mr. Brownlow sets out to find Oliver's parentage and inheritance.
When Nancy returns to the bridge where she had spoken with Rose, Brownlow speaks with her; he tells her that he wants to learn the secret of Oliver's identity and he wants her to turn over Fagin. Refusing to betray either one, Nancy instructs Mr. Brownlow to travel to the Three Cripples, he will find Monks, whose description given by Nancy sounds familiar to him.
Brownlow arranges the kidnapping of Monks and talks with him, telling him that he knows that he is the son of a good friend of his. He informs Monks that he knows of the will that the man has made. To settle things, Mrs. Maylie, Rose, Mr. Losberne, and Mrs. Bedwin travel toward Oliver's birthplace; behind them, Mr. Brownlow and Monks follow. In a meeting, Mr. Brownlow tells Monks,
"This child is your half-brother; the illegitimate son of your father, my dear friend Edwin Leeford, by poor young Agnes Fleming, who died in giving him birth."
After Monks says that his mother burned the will, and he swore to her that he would find the child, if it lived, and make its life a misery,the brave Brownlow reveals all he knows about Monks, convincing him to cooperate in giving Oliver his inheritance, or he will turn Monks over to the authorities, providing them with his information. Mr. Brownlow tells Monks to remain while he has a document drawn up.
After Oliver's inheritance is restored to him, Mr. Brownlow adopts Oliver has his son and they continue to live with Mrs. Bedwin, close to Rose, who turns out to be Oliver's aunt. Mr. Brownlow has given Oliver Twist legitimacy, his inheritance, and, above all, his love and friendship.