Ethel Dell's married name is recorded as Ethel Mary Savage. She was born in Streatham, a suburb of London. Her father was a clerk in the City of London and she had an older sister and brother. Her family was middle class and lived a comfortable life. Ethel Dell was a very shy, quiet girl and was content to be dominated by her family. She began to write stories while very young and many of them were published in popular magazines. Beneath her shy exterior, she had a passionate heart and most of her stories were stories of passion and love set in India and other British colonial possessions. They were considered to be very racy and her cousins would pull out pencils to try and count up the number of times she used the words: passion, tremble, pant and thrill.

Ethel Dell worked on a novel for several years, but it was rejected by eight publishers. Finally the publisher T. Fisher Unwin bought the book for their First Novel Library, a series which introduced a writer's first book. This book, titled The Way of an Eagle, was published in 1912 and by 1915 it had gone through thirty printings.

The Way of an Eagle is very characteristic of Ethel M. Dell's novels. There is a very feminine woman, an alpha male, a setting in India, passion galore liberally mixed with some surprisingly shocking violence and religious sentiments sprinkled throughout.

While readers adored Ethel M. Dell's novels, critics hated them with a passion; but she did not care what the critics thought. She considered herself a good storyteller — nothing more and nothing less. Ethel M. Dell continued to write novels for a number of years. She made quite a lot of money, from 20,000 to 30,000 pounds a year, but remained quiet and almost pathologically shy.

Pictures of her are very rare and she was never interviewed by the press. She married a soldier, Lieutenant-Colonel Gerald Savage, when she was forty years old, and the marriage was happy. Colonel Savage resigned his commission on his marriage and Ethel Dell became the support of the family. Her husband devoted himself to her and fiercely guarded her privacy. For her part she went on writing, eventually producing about thirty novels and several volumes of short stories. Her readers remained loyal and the critics simply gave up. Ethel M. Dell died of cancer when she was fifty-eight.

• George Orwell, in his novel Keep the Aspidistra Flying, has his protagonist make several scathing comments about Dell and others (notably, Warwick Deeping) and reserves special venom for The Way of an Eagle. He refers to her in answers to a questionnaire The Cost of Letters (1946) on the subject of a serious writer earning a living by writing.

• Winifred Watson, in her novel Miss Pettigrew Lives for a Day, has the titular character refer to Dell as the source of her inspiration to encourage a young gentleman to punch a rival by hissing, "Sock him one" at the key moment.

• P. G. Wodehouse burlesqued her in several of his stories as the recurring character Rosie M. Banks. Wodehouse's main character Bertie Wooster refers to Rosie as a writer of "the world's worst tripe"; his valet Jeeves concurs and opines that he somehow prefers the Russian novelists.

• In James Joyce's Ulysses Gerty MacDowell's free indirect monologuing is written in the style of an Ethel M. Dell novel.

Wodehouse mentions Dell by name in his novel Uncle Dynamite (1948), whose diffident hero, Bill Oakshott, is several times encouraged to model himself on the masterful man in The Way of an Eagle.

He also wrote the short story "Honeysuckle Cottage", which uses themes and characters very like those of Ethel M. Dell. In it, a writer of Raymond Chandler-like hard-boiled detective stories finds to his horror that his work (and later his whole life) is being possessed by characters who seem to come out of a syrupy romance novel by "Leila M. Pinkney". Here is a sample:

He shoved in a fresh sheet of paper, chewed his pipe thoughtfully for a moment, then wrote rapidly:

“For an instant Lester Gage thought that he must have been mistaken. Then the noise came again, faint but unmistakable.

His mouth set in a grim line. Silently, like a panther, he made one quick step to the desk, noiselessly opened a drawer, drew out his automatic. After that affair of the poisoned needle, he was taking no chances. Still in dead silence, he tiptoed to the door; then, flinging it suddenly open, he stood there, his weapon poised.

On the mat stood the most beautiful girl he had ever beheld. A veritable child of Faërie. She eyed him for a moment with a saucy smile; then with a pretty, roguish look of reproof shook a dainty forefinger at him. ‘I believe you've forgotten me, Mr. Gage!’ she fluted with a mock severity which her eyes belied.”

James stared at the paper dumbly.

—P. G. Wodehousefrom "Honeysuckle Cottage" in Meet Mr Mulliner (1927)

• The Way of an Eagle (1912)
• The Knave of Diamonds (1912)
• Greatheart (1912)
• The Rocks of Valpré (1914)
• The Keeper of the Door (1915)
• The Bars of Iron (1916)
• The Hundredeth Chance (1917) - also as The Hundredth Chance
• The Rose of Dawn (1917)
• The Safety Curtain and Other Stories (1917) - collection
• The Lamp in the Desert (1919)
• The Tidal Wave and Other Stories (1920) - collection
• The Desire of His Life (1920)
• The Top of the World (1920)
• The Obstacle Race (1921)
• Rosa Mundi and Other Stories (1921) - collection
• The Knight Errant (1922) - 1922 movie, novel's date uncertain
• The Odds and Other Stories (1922) - collection
• Charles Rex (1922)
• Verses (1923)
• The Swindler and Other Stories (1923) - collection
• Tetherstones (1923)
• The Unknown Quantity (1924)
• The Passer-By and Other Stories (1925)
• A Man Under Authority (1926)
• The Black Knight (1926)
• The House of Happiness and Other Stories (1927) - collection
• The Gate Marked Private (1928)
• By Request (1928) - U.S. title Peggy by Request
• The Altar of Honour (1929)
• Storm Drift (1930)
• The Silver Bride (1932) — U.S. title The Silver Wedding (1933)
• The Live Bait and Other Stories (1932) - collection
• Dona Celestis (1933)
• The Prison Wall (1933)
• The Electric Torch (1934)
• Where Three Roads Meet (1935)
• Honeyball Farm (1937)
• The Juice of the Pomegranate (1938)
• The Serpent in the Garden (1938)
• Sown Among Thorns (1939)

Additional, uncertain titles found in some lists:

• The Princess's Game (1920)
• The Lucky Number (1920)
• Pullman (1930)