Reneisha Wilkes, 25, of San Bernardino was on the show in 2010 when DeGeneres awarded Wilkes a new car for her volunteer work providing funding and transportation resources to low-income residents, seniors and veterans.
Wilkes, who works as a student resources coordinator for the San Joaquin Valley College campus in Rancho Cucamonga, has provided hours of free community service to people in need since she was in high school.
"You have done more community service than anyone under the age of 25 in Southern California," DeGeneres said during Wilkes' 2010appearance.
"I would like you to be my first official Ellen volunteer of the month and I'm giving you this plaque ... also a brand new car."
Wilkes' appearance this week was part of a celebration of the show's 10-year anniversary. The week saw DeGeneres inviting other guests such as first lady Michelle Obama, Justine Bieber, and Kelly Clarkson, in addition to showing memorable clips from the past decade.
Wilkes earned another $10,000, along with a large framed certificate as DeGeneres' volunteer of the year.
DeGeneres asked Wilkes how the car was doing.
"It's doing great, thank you so much, Ellen, you changed my life," Wilkes said.
"I was taking public transportation. I was getting up three or four hours early just to get to the bus stop, and sometimes in rain. I told you I just appreciate everything you have done for me."
Wilkes has a program where she and other volunteers give rides to veterans and senior citizens for trips to the grocery store.
"Veterans need rides," Wilkes said.
"They've been injured overseas. They served our country. I don't feel they should have to walk to get to the doctor's and grocery store. I believe there should be a ride for serving our country. That's the least we can do. We do the same for seniors."
She also said she used her initial $10,000 to help pay for school tuition, gave $1,000 to her church, and $1,000 toward giving Christmas presents to her friends' children.
This time around, Wilkes said she'll use the money to help pay off bills. Wilkes is also engaged to be married in March.
People can reach Wilkes through her website, someonehelpedmehelps.wordpress.com.
Reach Neil via email, call him at 909-483-9356, or find him on Twitter @InlandGov.