Use BLOND (noun) for males.
If you’re referring a boy or a man with golden-colored hair or very light brown-haired use blond (no E).
• The handsome man is a blond.
• He’s a tall, blue-eyed blond.
Use BLONDE (noun) females
However, if you’re referring a golden-haired girl or very light brown-haired woman, use blonde (with the E).
• Marilyn Monroe is a blonde.
• She’s a natural blonde.
Use BLOND (adjective) for males and/or females
When you simply want to use an adjective to describe a person as being blond? As an adjective, blond never has an E at the end. It’s always simply blond.
• The blond man walked through the door.
• The blond woman just passed me by.
Wonder why we have two spellings of this noun? Blame the French. French regularly assigns gender to words and spells them differently based on whether they are masculine or feminine. Since we inherited the word blond and blonde from French, we also inherited the two ways of spelling it.
Dumb blonde cliché started with the kinds of characters of Marilyn Monroe played in many of her movies. She usually played characters who were pretty ditsy (unintelligent), though sometimes she came through with some profoundly wise insights.
Here’s one of my favorite blonde jokes ever:
Brunette : I’ll be the first brunette to step on Mars.
Ginger : I’ll be the first ginger to step on Venus.
Blonde : I’ll be the first blonde to land on the sun.
Brunette & Ginger : But you’ll burn!
Blonde : Don’t be stupid! I’ll go at night. 😀