At the time of The Age of Innocence's publication, Wharton was already a well-respected author. Her readers and critics expected much of her, and they were generally impressed with her new novel. They found the characters realistic and interesting, and Wharton's ability to capture the details, mood, and rigors of New York society life was praised by readers and literary critics alike. In a 1920 New York Times Book Review, William Lyon Phelps applauds the novel, noting, "I do not remember when I have read a work of fiction that gives the reader so vivid an idea of the furnishing and illuminating of rooms in fashionable houses as one will find in The Age of Innocence." He adds, "New York society and customs in the seventies are described with an accuracy that is almost uncanny."

Besides providing a vibrant piece of social history, Wharton's novel told a compelling story complete with universal themes and comments on the complexities of human interaction. Margaret B. McDowell in Twayne's United States Authors Series writes that the novel is "at once a masterful evocation of a milieu and a masterful delineation of human beings caught between renunciation and passion." In The Two Lives of Edith Wharton: The Woman and Her Work, Grace Kellogg-Griffith remarks, "Mrs. Wharton portrayed the society of her young womanhood with a clarity and a firmness of outline that have given them life and permanent importance. The Age of Innocence is a flawless piece of artistry."

Equally enthusiastic was Phelps, who concludes that "Edith Wharton is a writer who brings glory on the name America, and this is her best book." The critic went on to comment that this novel lacks the flaws typically found in Wharton's novels, such as relentless witticisms, unbelievable coincidences, and seemingly rushed scenes. Critics noted that Wharton depicts New York with a sympathetic yet scolding tone that is wholly appropriate. One of Wharton's contemporaries, Carl Van Doren, author of Contemporary American Novelists 1900-1920, observes:

From the first Mrs. Wharton's power has lain in the ability to reproduce in fiction the circumstances of a compact community in a way that illustrates the various oppressions which such communities put upon individual vagaries, whether viewed as sin, or ignorance, or folly, or merely as social impossibility.

Critics such as Cynthia Griffin Wolff of Dictionary of Literary Biography Volume Nine: American Novelists, 1910-1945 described The Age of Innocence as a bildungsroman, which is a novel that depicts a character's growth from adolescence into adulthood. Wolff argued that it is Newland whose growth into maturity is witnessed in Wharton's novel. She added that his experience is unique because of the narrow environment in which he matures. As a result, the restrictive setting can be viewed as meaningful, providing necessary structure to everyday life and to Newland's passage into manhood.

Some critics found notable flaws in The Age of Innocence. In fact, two of the members of the Pulitzer Prize committee thought the prize should have gone to another author in 1921 instead of Wharton. They believed the book to be overly specific to a time and place. As a result, they argued, the book lacked universal relevance. Other critics took this stance a step further, adding that the book is limited because it is about a community of people who were far removed from the norm, even in their own time and place.

Arthur Mizener in Twelve Great American Novels comments that The Age of Innocence , while "very nearly a great novel," is weakened by heavy-handed cleverness. He found the worst example to...