Gitanjali Rao is an American inventor, author, social activist, and a STEM student and advocate.

She won the Discovery Education 3M Young Scientist Challenge in 2017 and was recognized on Forbes 30 Under 30 for her innovations.[3] Rao was named Time's top young innovator of 2020 for her innovations and "innovation workshops" she conducts across the globe[4] and, on December 4, 2020, was featured on the cover of Time and named their first "Kid of the Year".

Rao was first influenced by a science kit her uncle gave to her when she was 4 years old.When she was 10, she heard about the Flint water crisis while watching the news and became interested in ways to measure the lead content in water. This led to her using App Inventor to develop a device called Tethys which was based on carbon nanotubes that could send water quality information via Bluetooth. She collaborated with a research scientist at 3M and in 2017, she won the Discovery Education 3M Young Scientist Challenge and was awarded $25,000 for her invention, Tethys.