Gitanjali Rao, from Denver, Colorado, has invented a number of new technologies across a range of fields, including a device that can identify lead in drinking water and an app and Chrome extension that uses artificial intelligence to detect cyberbullying.
She said she hoped she could inspire others into dreaming up ideas to “solve the world’s problems”.
In an interview with Angelina Jolie, Gitanjali said: “I don’t look like your typical scientist. Everything I see on TV is that it’s an older, usually white man as a scientist.
“My goal has really shifted, not only from creating my own devices to solve the world’s problems, but inspiring others to do the same as well.
“Because, from personal experience, it’s not easy when you don’t see anyone else like you.
“So I really want to put out that message: If I can do it, you can do it, and anyone can do it.”
Time began awarding its Man Of The Year honour – later updated to Person Of The Year – in 1927, but this is the first time it has named a Kid Of The Year.
Time, which also produces the child-friendly Time For Kids, teamed up with children’s TV channel Nickelodeon for the new award.
Gitanjali was chosen from a field of 5,000 US-based nominees, which was whittled down to five finalists by a committee of young people alongside comedian and TV presenter Trevor Noah.
She and the other four finalists will be honoured in a TV special next Friday.