The 71-year-old Leo had the lower lobe of his right lung removed after doctors identified a suspected cancerous nodule.
The surgery confirmed he had adenocarcinoma, the most common type of lung cancer.
His personal physician and surgeon said in a separate statement that Leo was "deemed fit for discharge from the hospital" based on blood test results and a chest X-ray performed on Saturday morning along with an assessment of his clinical condition.
He was set to leave Gemelli hospital in the early afternoon and return to the Vatican, the Vatican said in a brief statement.
With notable transparency, Leo announced last Sunday to the faithful gathered in St Peter's Square that doctors had identified a nodule on his lung, and that it would be removed.
Since the surgery on Tuesday that confirmed the cancer diagnosis, Leo has given strong indications that he was recovering well, including by holding a phone call with Russian President Vladimir Putin, meeting top aides and celebrating mass in a hospital chapel.
Spare medical bulletins from his personal physician and surgeon likewise indicated a good post-operative recovery that had allowed him to carry on "normal daily activities completely on his own".
The Vatican on Friday released the first images of Leo since his lung cancer surgery, showing him standing up at an altar in a hospital chapel in green vestments, as doctors said that tests confirmed his "continued improvement".
Leo presided alone over the liturgy, distributing communion to medical personnel and Vatican gendarmes present, Vatican spokesman Matteo Bruni said.
He also delivered a homily in which he thanked the hospital staff "for the work they do every day taking care of the sick in their fragility, and in a particular way what they had done for him", Bruni said.
The Vatican had originally estimated a week-long hospital stay, and had cancelled his audiences through Tuesday.
Bruni said the discharge date was up to the Pope's doctors.
The Pope's next big agenda item is a trip to Latin America from November 6 to 17, which gives Leo three more weeks of recovery before taking on the ambitious journey that includes a dozen flights and two helicopter trips.
The Vatican has given signs of all systems go, publishing the names of journalists accredited to fly on Leo's plane on Friday.
And oncology surgeons say protocols generally clear patients to fly after three weeks, as long as recovery allows.
Doctors are still awaiting the results of tests to understand the precise molecular and genetic make-up of the cancer, whether it has spread beyond the lobe and whether any further treatment is necessary.
