Bonino, who had been tipped as a contender for Italy's presidency before announcing she was ill, said has been given the all-clear by medics.
“The medical report contained good news – the clinical tests in the last few days showed that all evidence of cancer has disappeared,” she was quoted by La Repubblica as saying.
“It's the best news I could have hoped for.”
Bonino said she will now undergo preventive radiotherapy on the brain as well as rest for a long period of time to avoid the “high risk of relapse of this type of cancer” within the first year of treatment.
“But this has certainly been a good day for me.”
She added that as soon as she's feeling stronger, she'll dedicate time to politics.
She also thanked the medical team while extending encouragement and well wishes to cancer sufferers.
Twitter was flooded with words of joy from Bonino's supporters.
"A big hug to #EmmaBonino, a great fighter also against cancer. Her announcement is a great joy," wrote Health Minister Beatrice Lorenzin.
Bonino was one of 100 women chosen by the BBC in 2013 as someone who has "campaigned for her causes and striven for a better world".
Her campaigning helped towards Italy legalizing abortion in 1978. Bonino herself had an illegal abortion in the 1970s after becoming pregnant by a man who said he was sterile. A doctor then refused the procedure unless she paid him one million lire.
She was also instrumental in pushing for a referendum against nuclear energy that led to Italy rejecting a civil nuclear energy programme in 1986 and has been a tireless campaigner for the rights of repressed women in the Middle East.