Yes. Check out these opportunities.
Children's Magazines and Ezines
A good place to look is at the magazines you read. Do you see a kid's or children's section? Or there might be a "reader's art" section. Here are some I found:
Amazing Kids! Online Magazine - writing, art, photography or videography, by kids ages of 5 to 18.
chixLIT - by and for girls 13-17 OR chixLITtle for girls 7-12.
Creative Kids Magazine - for kids 8 to 16. "Material may include cartoons, songs, stories between 500 and 1200 words, puzzles, photographs, artwork, games, editorials, poetry, and plays, as well as any other creative work that can fit in the pages of the magazine."
Stone Soup Magazine - features stories, poems and art by kids 8 to 13
Contests aimed at children are a good place for young people to submit. Here are a few.
The Young Voices Foundation 2013 contest ends February 28th. This year's theme is: Young Voices of America Speak of Heroes Among Us
Adventure Write Kids has an annual contest for kids under the age of 19.
Creative Communication offers poetry and essay contests for kids ages K-12.
Miss Literati offers writing contests and book giveaways.
National Geographic Kids has some contests - looks as if photos is a consistent contest and others vary.
PBS Kids has a story writing and illustrating contest for kids in K-3rd grade.
The Young Writer's Guide to Getting Published by Kathy Henderson has been a good resource in the past, but the copy on Amazon is pretty dated (2001)
Young Writers Society is an online communities for young writers - ages 13+
Same as with adults submitting, kids and teens need to follow the directions exactly.