* jaune (yellow)
* jaloux (jealous)
* jeune (young)
* joli (pretty, handsome)
* juste (just, fair)
There are a few less common adjectives that start with "j" but they are mostly technical or specific terms, such as:
* judaïque (Jewish)
* jurassien (from the Jura region of France)
* juteux (juicy)
It's important to note that some words that start with "j" in English are not adjectives in French. For example, "jungle" is not an adjective in French, but a noun.