The 91-year-old Nobel peace laureate and global humanitarian recently had a tumor from his liver removed, only to find four melanoma spots on his brain.
"Went for an MRI this past week and they (doctors) didn't find any cancer at all in the brain," Carter said, according to NBC News.
A friend and parishioner of Carter's told the Atlanta Journal-Constitution that he made the announcement towards the beginning of the Sunday school class he leads at Maranatha Baptist Church in Plains.
Last month the Carter Center said the 39th president was responding well to treatment and that there was no evidence of new growth.
Also Read
The former Democratic president won plaudits when he discussed his illness publicly in August, sounding serene and in high spirits, smiling often and joking with reporters in a thick Georgia drawl.
"You know, I have had a wonderful life. I have got thousands of friends and I have had an exciting and adventurous and gratifying existence," Carter said.
Meanwhile the Atlanta Braves baseball team congratulated Carter on Twitter, writing "We are so happy to hear that you are cancer-free, Mr. President!"
Several of Carter's relatives died of pancreatic cancer, which tends to show up earlier in life.
Carter, a onetime peanut farmer and former Georgia governor, served one term as Us president, from 1977 to 1981.