A boat-load of Knock-Knock jokes (only for those with young children)

Knock knock
Who's there?
Hallo.
Hallo who?
Halloween.

Knock knock
Who's there?
Hair.
Hair who?
Hair today and gone tomorrow.

Knock knock
Who's there?
Habit.
Habit who?
Habit your way.

Knock knock
Who's there?
Gretta.
Gretta who?
Gretta long, little doggie, gretta long.

Knock knock.
Who's there?
Gorilla.
Gorilla who?
Gorilla my dreams, I love you.

Knock knock
Who's there?
Gopher.
Gopher who?
Gopher your gun, Marshal!

Knock knock
Who's there?
Holly
Holly who?
Holly Louya.

Knock knock
Who's there?
Honeydew and cantaloupe
Honeydew and cantaloupe who?
Honeydew you love me? We cantaloupe now.

Knock knock
Who's there?
Howl
Howl who?
Howl it be if I come to your house today?

Knock knock
Who's there?
Hugh
Hugh who?
Hugh Mility.

Knock knock
Who's there?
Hugo
Hugo who?
Wherever Hugo, I go, too.

Knock knock
Who's there?
Hume.
Hume who?
Hume do you expect?

Knock knock
Who's there?
Humphrey.
Humphrey who?
Humphrey ever blowing bubbles.

Knock knock
Who's there?
Idaho.
Idaho who?
Idaho my own name.

Knock knock
Who's there?
I don 't know. I didn't open the door yet.

Knock knock
Who's there?
Imus.
Imus who?
Imus get out of this rain.

Knock knock
Who's there?
Iona.
Iona who?
Iona new car,

Knock knock
Who's there?
Ira.
Ira who?
Ira member Mama.

Knock knock
Who's there?
Iran.
Iran who?
Iran all the way home.

Knock knock
Who's there?
Ireland.
Ireland who?
Ireland you a quarter if you promise to pay me back.

Knock knock
Who's there?
Isabel.
Isabel who?
Isabel out of order?

Knock knock
Who's there?
Isadore.
Isadore who?
Isadore locked?

Knock block
Who's there?
Israeli.
Israeli who?
Israeli great to see you again.

Knock knock
Who's there?
Ivan.
Ivan who?
Ivan to hold your hand

Knock knock
Who's there?
Ivan.
Ivan who?
Ivan working on the railroad, all the livelong day.

Knock knock
Who's there?
Ivan.
Ivan who?
Ivan wanting to drop over.

Knock knock
Who's there?
Ivy League.
Ivy League who?
Ivy League for every drop of rain that falls, a flower grows.

Knock knock
Who's there?
Jacket.
Jacket who?
Jacket up if you've got aflat tire.

Knock knock
Who's there?
Jess.
Jess who?
Jess little old me.

Knock knock
Who's there?
Jose.
Jose who?
Jose, can you see, by the dawn 's early light?

Knock knock
Who's there?
Juicy.
Juicy who?
Juicy any ghosts in the haunted house?

Knock knock
Who's there?
Juneau.
Juneau who?
Juneau the capital of Alaska?

Knock knock
Who's there?
Kangar.
Kangar who?
You will find them in Australia.

Knock knock
Who's there?
Karen
Karen who?
Karen a bundle of bricks isn't much fun.

Knock knock
Who's there?
Kay
Kay who?
Kay sera sera.

Knock knock
Who's there?
Kerch.
Kerch who?
Gesundheit!

Knock knock
Who's there?
Ketchup.
Ketchup who?
Ketchup with me and I'll tell you.

Knock knock
Who's there?
Ketchup.
Ketchup who?
Ketchup to her before she turns the comer.

Knock block
Who's there?
Kleenex
Kleenex who?
Kleenex are pratier than dirty necks.

Knock knock
Who's there?
Lego.
Lego who?
Lego the door— I wanna come in

Knock knock
Who's there?
Lesson
Lesson who?
Lesson here and I'll tell you a knock knock joke

Knock knock
Who's there?
Lettuce,
Lettuce who?
Lettuce pray.

Knock knock
Who's there?
Linda
Linda who?
Linda me some money, please

Knock block
Who's there?
Lion.
Lion who?
Lion on a cold slab can be deadly!

Knock knock
Who's there?
Lion.
Lion who?
Lion down on the job, eh?

Knock knock
Who's there?
Lionel
Lionel who?
Lionel roar if you don 't feed him.

Knock knock
Who's there?
Marcella.
Marcella who?
Marcella 's full of water. Call a plumber.

Knock knock.
Who's there?
Marsha.
Marsha who?
Marsha-mallow.

Knock knock.
Who's there?
Max.
Max who?
Max no difference. Let me in.

Knock knock.
Who's there?
Mayonnaise.
Mayonnaise who?
Mayonnaise have seen the glory of the coming of the Lord

Knock knock
Who's there?
Me.
Me who?
Don't you know your own name?

Knock knock
Who's there?
Mecca.
Mecca who?
Mecca noise like  a duck

Knock knock
Who's there?
Mississippi.
Mississippi who?
Mississippi and Mr. Sippy. Can we come in?

Knock knock
Who's there?
Missy.
Missy who?
Missy-laneous.

Knock knock
Who's there?
Monopoly
Monopoly who?
Monopoly's bigger than your nopoly.

Knock knock
Who's there?
Morris.
Morris who?
Morris Monday; next day's Tuesday.

Knock knock
Who's there?
Moscow.
Moscow who?
Moscow gives more milk than Pa 's cow.

Knock knock
Who's there?
Mountie.
Mountie who?
Mountie horses and go for a ride.

Knock knock
Who's there?
Mush
Mush who?
Mush be twenty-past eight.

Knock knock
Who's there?
My panther.
My panther who?
My panther falling down. I need a belt.

Knock knock
Who's there?
My Tommy.
My Tommy who?
My Tommy aches.

Knock knock
Who's there?
Navajo.
Navajo who?
You'II Navajo until you open the door.

Knock knock
Who's there?
Needle.
Needle who?
Needle little money for the movies.

Knock knock
Who's there?
Newton.
Newton who?
Newton doing.

Knock knock
Who's there?
Nicholas.
Nicholas who?
Nicholas half as much as a dime.

Knock knock
Who's there?
Noah
Noah who?
Noah good place to eat around here?

Knock knock
Who's there?
Nobody.
Thank goodness!

Knock knock
Who's there?
Nobody. I'm just banging on the table.

Knock knock
Who's there?
November.
November who?
November when we used to tell knock knock jokes?

Knock knock
Who's there?
Nunna.
Nunna who?
Nunna your business.

Knock knock
Who's there?
Odyssey.
Odyssey who?
Odyssey a dentist if your mouth hurts.

Knock knock
Who's there?
Olga.
Olga who?
Olga round to the back door.

Knock knock
Who's there?
Olive.
Olive who?
Olive you, too, honey.

Knock knock
Who's there?
Abbot
Abbot who?
Abbot you don't know who this is!

Knock knock.
Who's there?
Abe Lincoln.
Abe Lincoln who?
Dummy! Don 't you know who Abe Lincoln is?

Knock knock.
Who's there?
Ach.
Ach who?
God bless you!

Knock knock
Who's there?
A cheetah.
A cheetah who?
A cheetah never wins.

Knock knock
Who's there?
Adam.
Adam who?
Adam up and get the total.

Knock knock
Who's there?
Adele.
Adele who?
Adele is where the farmer's in.

Knock knock
Who's there?
Adore.
Adore who?
Adore is between us. Open up.

Knock knock
Who's there?
Agatha.
Agatha who?
Agatha feeling you 're fooling.

Knock knock
Who's there?
Ahead.
Ahead who?
Ahead is on your shoulders,

Knock knock.
Who's there?
Cargo.
Cargo who?
Cargo beep and ran over the Ether bunny

Knock knock
Who's there?
Boo who?
Don 't cry — Ether bunny be back next year.

Knock knock
Who's there?
Etta.
Etta who?
Etta Kett.

Knock knock
Who's there?
Eva
Eva who?
Eva since yesterday I've been knocking

Knock knock
Who's there?
Eyewash.
Eyewash who?
Eyewash I had a million dollars.

Knock knock
Who's there?
Fang.
Fang who?
Fang you very much

Knock knock
Who's there?
Ferry.
Ferry who?
Ferry tales can come true.

Knock knock
Who's there?
Finish.
Finish who?
Finish it yourself

Knock knock
Who's there?
Fire engine.
Fire engine who?
Fire engine one and prepare for blast-off

Knock knock
Who's there?
Formosa.
Formosa who?
Formosa the term I was absent from school.

Knock knock
Who's there?
Freeze.
Freeze who?
Freeze a jolly good fellow.

Knock knock
Who's there?
Gary.
Gary who?
Gary me back to old Virginny.

Knock knock
Who's there?
Gibbon.
Gibbon who?
Gibbon take if you want to get along in the world.

Knock knock
Who's there?
Gladys.
Gladys who?
Gladys Friday—how bout you?