Bezos, who is also the owner of the space rocket company Blue Origin, announced the award on Friday along with his partner, news anchor Lauren Sanchez.
Sanchez said on Instagram that Parton is "a woman who gives with her heart and leads with love and compassion in every aspect of her work".
"We can’t wait to see all the good that you’re going to do with this $100m award," she said.
Parton, in a video clip of the ceremony posted online, said: "Wow! Did you say $100m?"
"I think people who are in a position to help should put their money where their heart is. I will do my best to do good things with this money," she said.
Parton, 76, a country, pop and gospel singer-songwriter, whose songs include 9 to 5 and Jolene, has been a philanthropist for many years.
She donated $1m to Vanderbilt University's Medical Centre to help develop a vaccine during the Covid-19 pandemic.
Parton, who this month was inducted into the Rock & Roll Hall of Fame, has also founded a number of charities including the Dollywood Foundation, which focuses on education as well as poverty relief.
Bezos first handed out the award in 2021, honouring activist Van Jones, who served as founding chief executive of the Reform Alliance and Dream Corps, as well as chef and humanitarian Jose Andres, who established World Central Kitchen, which provides food in the immediate aftermath of disasters.