For all its irreverence and blasphemy, the religious satire “The Little Hours” has something of a nostalgic vibe.

It has the same brazen and utterly sacrilegious tone of “Monty Python and the Holy Grail” and “Monty Python’s Life of Brian.” (Though it’s not in the same league. Then again, very few comedies of ANY kind are in that league.) Writer-director Jeff Baena clearly couldn’t give a hoot whether his ribald tale of Nuns Gone Wild will offend — and that’s a relatively rare thing in these sensitive and oh so politically correct times.

Based quite loosely on Bocaccio’s collection of stories titled “The Decameron” and set in 14th century Italy, “The Little Hours” has some wonderfully anachronistic and tart dialogue; bold and sharp and very funny work from an outstanding ensemble cast including alums from “Parks and Recreation,” “Saturday Night Live” and “Community,” and yes, a few salient albeit obvious points about sanctimony and hypocrisy cloaked in the vestments of organized religion.

The wonderful deadpan sharpshooter Aubrey Plaza is in her comfort zone and knocks it out of the park as Sister Fernanda, the Alpha Nun of a trio that includes the sweet and starry-eyed Sister Alessandra (Alison Brie) and the snarky and snitch-y Sister Ginevra (Kate Micucci).

In an opening moment setting the tone for the entirety of the story, a kindly groundskeeper pauses from his chores to innocently say to the nuns, “It’s a beautiful morning, sisters.”

This sends Sister Fernanda into a foul-mouthed rage that’s ridiculous and unwarranted and brutal and flat-out funny: “Hey, don’t f—ing talk to us, f—ing creep! Now get the f— out of here!”

Off scurries the groundskeeper, while the nuns return to doing the work of the Lord.

Plaza’s “Parks and Rec” pal Nick Offerman plays the ruthless and quite twisted Lord Bruno, who is out to kill the workman Massetto (Dave Franco) after Bruno’s wife Francesca (Lauren Weedman) seduces Massetto.

On the run, Massetto encounters Father Tommasso (John C. Reilly), who offers Massetto refuge as a hired hand at the convent — but says Massetto must pretend to be deaf and mute in order to minimize communication and reduce temptation with the nuns.

Not the greatest plan ever hatched.

From the moment Massetto arrives on the scene, plunked into the middle of a remote setting where a number of sexually repressed women regard him as the meal they’ve been waiting for, “The Little Hours” is not unlike “The Beguiled” played for laughs. Even with generous helpings of nudity and profanity, the sex scenes are played for laughs, sometimes to great effect, as when Sister Ginevra is driven nearly insane once her inner lust is unleashed.

The reliable Molly Shannon is terrific as Sister Marea, the hopelessly outmatched mentor to the young nuns. The sly and likable Fred Armisen shows up as a bishop who is horrified by the goings-on at the convent. (“This is the longest list of sins I’ve ever had. Eating blood? Do you think I’ve ever written down ‘eating blood’ before?”) Jemima Kirke from “Girls” oversees a pagan ritual in the woods, because movies such as this should definitely have a pagan ritual in the woods.

True, “The Little Hours” is essentially a one-joke comedy — but most of the jokes under the umbrellas of that one joke are pretty damn, I mean darn, funny.

★★★

Gunpowder & Sky presents a film written and directed by Jeff Baena. Rated R (for graphic nudity, sexual content and language). Running time: 90 minutes. Opens Friday at the Music Box Theatre. Baena and star Aubrey Plaza will do Q&A’s after the 7:20 p.m. Friday and 5 p.m. Saturday screenings.