The announcement comes less than three months after Rivian revealed its first two products — an all-electric pickup and SUV — at the LA Auto Show.
The financial details of Amazon’s investment were not disclosed.
"We're inspired by Rivian's vision for the future of electric transportation," said Jeff Wilke, Amazon CEO Worldwide Consumer.
"RJ has built an impressive organization, with a product portfolio and technology to match. We're thrilled to invest in such an innovative company."
Following the investment round, Rivian will remain an independent company.
The firm has a team of more than 750 people and four development centres across Plymouth, Michigan; San Jose, California; Irvine, California; and Surrey, England.
Additionally, the electric vehicle startup has a 2.6mn sq ft manufacturing plant in Normal, Illinois.
"This investment is an important milestone for Rivian and the shift to sustainable mobility," said RJ Scaringe, Rivian Founder and CEO.
"Beyond simply eliminating compromises that exist around performance, capability and efficiency, we are working to drive innovation across the entire customer experience.
Delivering on this vision requires the right partners, and we are excited to have Amazon with us on our journey to create products, technology and experiences that reset expectations of what is possible."