"There once was a man from Nantucket" is the opening line for many limericks, in which the name of the island of Nantucket creates often ribald rhymes and puns. The protagonist in the obscene versions is typically portrayed as well-endowed and hypersexualized. The opening line is so well known that it has been used as a stand-alone joke, implying upcoming obscenities.

The earliest published version appeared in 1879 in The Pearl, Volume 3 (September 1879^[1]):

There was a young man of Nantucket.
Who went down a well in a bucket;
The last words he spoke.
Before the rope broke,
Were, "Arsehole, you bugger, and suck it."

Another early published version appeared in 1902 in the Princeton Tiger written by Prof. Dayton Voorhees:^[2][3][4]

There once was a man from Nantucket
Who kept all his cash in a bucket.
    But his daughter, named Nan,
    Ran away with a man
And as for the bucket, Nantucket.

Other publications seized upon the "Nantucket" motif, spawning many sequels.^[5][6]

Among the best-known are:

But he followed the pair to Pawtucket,
The man and the girl with the bucket;
    And he said to the man,
    He was welcome to Nan,
But as for the bucket, Pawtucket.

Followed later by:

Then the pair followed Pa to Manhasset,
Where he still held the cash as an asset,
    But Nan and the man
    Stole the money and ran,
And as for the bucket, Manhasset.

The many ribald versions of the limerick are the basis for its lasting popularity. Many variations on the theme are possible because of the ease of rhyming "Nantucket" with certain vulgar phrases. The following example comes from Immortalia: An Anthology of American Ballads, Sailors' Songs, Cowboy Songs, College Songs, Parodies, Limericks, and Other Humorous Verses and Doggerel, published in 1927.^[7][8]

There was a young man from Nantucket
Whose dick was so long he could suck it.
    He said with a grin
    As he wiped off his chin,
"If my ear was a cunt I would fuck it."

The poem has become a staple of American humor. It is often used as a joking example of fine art, with the vulgarity providing a surprising contrast to an expected refinement, such as in the 2002 film Solaris, when George Clooney's character mentions that his favorite poem is the most famous poem by Dylan Thomas that starts with "There was a young man from Nantucket"; or Will & Grace season 8 episode 3 ("The Old Man and the Sea"), in which Grace criticizes her date's poem for its the lack of rhyme, and as an example, she recites the first two lines of the ribald version: "There once was a man from Nantucket... Something something something... Suck it."

Many jokes assume the audience knows the poem so well that they do not need to hear any actual lines to get the allusion, such as Gilmore Girls season 3 episode 8, when Lorelai Gilmore jokes about carving something dirty into a bathroom wall by saying "What rhymes with Nantucket?"; in Who's the Boss season 5 episode 23, there is talk about poetry class and Tony says about Angela "...last time she heard her name mentioned in a poem, it started with "There once was a man from Nantucket"..."; in the Tiny Toon Adventures episode "Wheel O' Comedy" when Babs Bunny asks Buster Bunny to say the magic chant before spinning the wheel, to which Buster begins reciting: "There once was a girl from Nantucket..." before she quickly cuts him off with: "Not that chant!"^[9] or a sketch from the eighth season episode of Robot Chicken titled "Not Enough Women", when J. R. R. Tolkien, writing the opening of the book The Hobbit, comes up with the line, "In a hole of Middle-earth, there was found a Hobbit... whose dick was so long, he could slob it." The fifth season episode of The Simpsons titled "Deep Space Homer" features a gag where Homer begins to recite the limerick while performing cartwheels in the NASA training gymnasium, but can only finish the first line before he collides with a wall. The 2012 Gravity Falls episode "Headhunters" features the line, "There once was a dude from Kentucky..." Broadcast Standards and Practices requested that the line be changed from “There once was a man from Kentucky”, which retained the sentence structure of the original limerick, arguing that "unsavory rhymes could be gleaned from it."^[10][11] In an episode of SpongeBob SquarePants however, SpongeBob, while preparing to recite an opera song, pulls out a piece of paper and reads, "There once was a man from Nantucket..." before the audience gasps in shock; he puts the paper back into his pocket, saying "Oops, wrong one", and afterward continuing with his song.

Frasier Crane, in the Frasier episode "The Botched Language of Cranes",^[12] is eager to find some humor to break the ice as he takes the role of host at a high-stakes church fundraiser that he hopes can repair his damaged reputation. Frustrated at drawing a mental blank, he quips ironically, "Why don't I call Bulldog and ask him for a couple of limericks from his Nantucket series?"

• Yesterday's Island "Limerick Challenge"