Guilty Bonds (1891)
Strange Tales of a Nihilist (1892)
The Great War in England in 1897 (1894)
The Temptress (1895)
Zoraida: A Romance of the Harem And the Great Sahara (1895)
The Great White Queen: a Tale of Treasure And Treason (1896)
A Secret Service: Being Strange Tales of a Nihilist (1896)
Devil's Dice (1897)
The Eye of Istar: a Romance of the Land of No Return (1897)
A Secret Sin (1897)
     aka A Madonna of the Music Halls
Whoso Findeth a Wife (1897)
If Sinners Entice Thee (1898)
Scribes and Pharisees: A Story of Literary London (1898)
The Bond of Black (1899)
The Day of Temptation (1899)
England's Peril (1899)
An Eye for an Eye (1900)
In White Raiment (1900)
The Wiles of the Wicked (1900)
Of Royal Blood (1900)
The Gamblers (1901)
The Sign of the Seven Sins (1901)
The Court of Honour (1901)
Her Majesty's Minister (1901)
The Under Secretary (1902)
The Unnamed: A Romance of Modern Italy (1902)
The Seven Secrets (1903)
The Tickencote Treasure: Being the Story of a Silent Man, a Sealed Script And a Singular Secret (1903)
Three Glass Eyes (1903)
As We Forgive Them (1904)
The Closed Book: Concerning the Secret of the Borgias (1904)
The Hunchback of Westminster (1904)
The Idol of the Town (1904)
The Man from Downing Street (1904)
The Red Hat (1904)
The Sign of the Stranger (1904)
Behind the Throne (1905)
The Mask (1905)
The Spider's Eye (1905)
The Valley of the Shadow (1905)
The Czar's Spy (1905)
Sins of the City (1905)
Who Giveth This Woman? (1905)
The Mysterious Mr Miller (1906)
The Invasion of 1910: With a Full Account of the Siege of London (1906)
The House of the Wicked (1906)
The Mystery of a Motor-Car (1906)
Whatsoever a Man Soweth (1906)
The Woman at Kensington (1906)
The Great Court Scandal (1907)
The Secret of the Square (1907)
The Woman in the Way (1907)
The Great Plot (1907)
The Crooked Way (1908)
Stolen Sweets (1908)
The Looker-On (1908)
The Pauper of Park Lane (1908)
The House of Whispers (1909)
The Red Room (1909)
Fatal Thirteen (1909)
Lying Lips (1910)
Treasure of Israel (1910)
     aka The Great God Gold
The Invasion (1910)
The Unknown Tomorrow (1910)
Hushed Up! (1911)
The Indiscretions Of A Lady's Maid (1911)
The Money-Spider (1911)
Fatal Fingers (1912)
The Mystery of Nine (1912)
Without Trace (1912)
The Room of Secrets (1913)
The Lost Million (1913)
The Price of Power (1913)
The Hand of Allah (1914)
     aka The Riddle of the Ring
The Four Faces (1914)
The German Spy (1914)
Her Royal Highness (1914)
The Maker of Secrets (1914)
Sons of Satan (1914)
The White Lie (1914)
The Double Shadow (1915)
The Mysterious Three (1915)
The Mystery of the Green Ray (1915)
The Sign of Silence (1915)
The White Glove (1915)
At the Sign of the Sword (1915)
The Broken Thread (1916)
The Place of Dragons (1916)
The Zeppelin Destroyer (1916)
Annette Of The Argonne (1916)
Cinders of Harley Street: Being Some Curious Leaves from the Diary of Villiers Beethom-saunders, M.d (1916)
The Man About Town (1916)
The Way to Win (1916)
Beryl of the Biplane (1917)
The Minister of Evil: The Secret History of Rasputin's Betrayal of Russia (1917)
No Greater Love (1917)
Rasputin the Rascal Monk: Disclosing the Secret Scandal of the Betrayal of Russia By the Mock-monk "grichka" And the Consequent Ruin of the Romanoffs : ... Revealed And Recorded for the First Time (1917)
The Secrets of Potsdam: A Startling Exposure of the Inner Life of the Courts of the Kaiser And Crown-prince Revealed for the First Time By ... Personal-adjutant to the German Crown-prince (1917)
Behind the German Lines: Amazing Confessions of Col.-lieut. Otto Von Heynitz, 16th Uhlans, Principal Aide-de-camp to His Imperial Highness the German ... of the Crown Prince's Shameful Actions (1917)
The Bomb-Makers: Being Some Curious Records Concerning the Craft And Cunning of Theodore Drost, an Enemy Alien in London, Together with Certain Revelations Regarding His Daughter Ella (1917)
The Breath of Suspicion (1917)
The Devil's Carnival (1917)
Hushed Up at German Headquarters (1917)
Two in a Tangle (1917)
The Catspaw (1918)
Sant of the Secret Service: Some Revelations of Spies And Spying (1918)
The Little Blue Goddess (1918)
The Lure of Love (1918)
The Sister Disciple (1918)
The Stolen Statesman (1918)
The Yellow Ribbon (1918)
The King's Incognito (1919)
Cipher Six (1919)
The Forbidden Word (1919)
Rasputinism in London: Revelations of the Secret Cult of Beauty And Happiness Established By the Monk Grichka, of Petrograd (1919)
Society Intrigues I Have Known: Astounding Facts Concerning Prominent People (1919)
The Doctor of Pimlico: Being the Disclosure of a Great Crime (1920)
The Heart of a Princess (1920)
The Intriguers (1920)
No. 7 Saville Square (1920)
The Red Widow (1920)
The Secret Telephone (1920)
Whither Thou Goest (1920)
The Terror of the Air (1920)
The Fifth Finger (1921)
The Lady in Waiting (1921)
Mademoiselle Of Monte Carlo (1921)
The Marked Man (1921)
The Luck of the Secret Service: Being the Startling Adventures of Claud Heathwaite, C.b., of His Britannic Majesty's Foreign Office (1921)
The Open Verdict (1921)
The Power of the Borgias (1921)
This House to Let (1921)
The Golden Face: A Great Crook Romance (1922)
The Stretton Street Affair (1922)
Three Knots (1922)
The Gay Triangle: The Romance of the First Air Adventurers (1922)
Tracked By Wireless (1922)
The Young Archduchess (1922)
The Bronze Face (1923)
     aka Behind the Bronze Door
Where the Desert Ends (1923)
The Voice from the Void: the Great Wireless Mystery (1923)
A Woman's Debt (1924)
Crystal Claw (1924)
Fine Feathers (1924)
The Broadcast Mystery (1925)
The Valrose Mystery (1925)
The Blue Bungalow (1925)
Blackmailed (1926)
The Letter E (1926)
     aka The Tattoo Mystery
The Black Owl (1926)
Hidden Hands (1926)
     aka The Dangerous Game
The Scarlet Sign (1926)
Double Nought (1927)
     aka The Crime Code
Poison Shadows (1927)
     aka The Chameleon
The Lawless Hand (1927)
The House of Evil (1927)
The Office Secret (1927)
Twice Tried (1928)
Concerning This Woman (1928)
The Rat Trap (1928)
The Secret Formula (1928)
The Sting (1928)
The Crinkled Crown (1929)
The Amazing Count (1929)
The Golden Three (1931)
Battle of Royston: From the Invasion of 1910 (1984)
The Captain of the Mary Rose: A Tale of Tomorrow (1999)

On the Polar Star in the Arctic Sea (1903)
The Balkan Trouble (1907)
     aka An Observer in the Near East
The War of the Nations (1914) (with Edgar Wallace)
German Spies in England: an Exposure (1915)
Britain's Deadly Peril: Are We Told the Truth? (1915)
The Devil's Spawn: How Italy Will Defeat Them (1915)
German Atrocities: a Record of Shameless Deeds (1915)
Further Secrets of Potsdam: Startling Exposures of the Inner Life of the Courts of the Kaiser And Crown-prince, Revealed for the First Time By Count Ernst Von Heltzendorff (1917)
The Secret Life of the Ex-Tsaritza: Amazing Disclosures By Her Maid-of-honour And Confidante (1918)
Love Intrigues of the Kaiser's Sons (1918)
Landru: His Secret Love Affairs (1922)
Things I Know About Kings, Celebrities, and Crooks (1923)
Great Stories of Real Life (1930) (with Edgar Wallace)
Dr. Crippen: lover And Poisoner (1966)

The Real Le Queux: The Official Biography of William Le Queux (1938) by Norman St. Barbe Sladen