"The Moon-Bog" is a short story by American horror fiction writer H. P. Lovecraft, written in or before March 1921. The story was first published in the June 1926 issue of the pulp magazine Weird Tales.

In the story, the unnamed narrator describes the final fate of his good friend, Denys Barry, an Irish-American who reclaims an ancestral estate in Kilderry, a fictional village in Ireland. Barry ignores pleas from the superstitious local peasantry not to drain the nearby bog, with unfortunate supernatural consequences.

The story was written at speed and to order, for oral delivery as an after-supper "shocker" for a Hub Club gathering of amateur journalists in Boston on March 10, 1921. The meeting had a St. Patrick's Day theme, and so required an Irish setting.

"The Moon-Bog" is described by S. T. Joshi and David E. Schultz as "one of the most conventionally supernatural in HPL's oeuvre."

As with many of Lovecraft's stories, "The Moon-Bog" has strong elements of his own autobiography woven into it - like Barry, Lovecraft had dreams of buying back his ancestors' home in England, and of reclaiming his standing among the landed gentry. The same theme is treated with greater depth in Lovecraft's more substantial story "The Rats in the Walls" (1923). There is also a further autobiographical element in "The Moon-Bog" - Lovecraft had seen his boyhood haunt of Cat Swamp purchased by the city authorities with the declared aim of protecting it from developers. But instead the city allowed it to be drained for development, and 200 new houses were erected on the site in 1919 .

Famous works of the author Howard Phillips Lovecraft: At the Mountains of Madness, The Dreams in the Witch House, The Horror at Red Hook, The Shadow Out of Time, The Shadows over Innsmouth, The Alchemist, Reanimator, Ex Oblivione, Azathoth, The Call of Cthulhu, The Cats of Ulthar, The Dunwich Horror, The Doom that Came to Sarnath, The Festival, The Silver Key, The Other Gods, The Outsider, The Temple, The Picture in the House, The Shunned House, The Terrible Old Man, The Tomb, Dagon, From Beyond, What the Moon Brings.

• Narrator: Peter Coates
• Listening Length: 20 minutes 27 seconds