The 15-year-old, who hails from Colorado, was selected from a field of more than 5,000 nominees and was interviewed by Hollywood actor Angelina Jolie.
Every year, the TIME magazine reveals its person of the year but this year it has revealed its first-ever Kid of the Year.
The step was an attempt to recognise extraordinary young leaders who are making a positive impact in their communities.
The young talent spoke about her innovation process, saying she follows a pattern of “observe, brainstorm, research, build, communicate”.
“Don’t try to fix every problem, just focus on one that excites you,” Gitanjali told TIME.
She also spoke about her mission to create a global community of young innovators to solve problems in the world.
The budding scientist said she was in second or third grade when she started thinking about how she can use science and technology to create social change. Upon turning 10, she told her parents that she wanted to research carbon nanotube sensor technology at the Denver Water Quality Research Lab.
TIME said: “Even over video chat, her brilliant mind and generous spirit shone through, along with her inspiring message to other young people: don’t try to fix every problem, just focus on one that excites you.”
Gitanjali said in the interview: “If I can do it, anybody can do it.”
The magazine said: “The world belongs to those who shape it. And however uncertain that world may feel at a given moment, the reassuring reality seems to be that each new generation produces more of what these kids…have already achieved: positive impact, in all sizes.”
TIME began awarding its man of the year honour in 1927, later updating it to person of the year. It teamed up with children’s TV channel Nickelodeon for the new award.
Last year, climate activist Greta Thunberg became the youngest ever person of the year when she was given the honour at the age of 16.
Gitanjali will be featured on the December 14 cover of TIME Magazine.