Keane, who leads the Ireland charts for all-time scorer and appearances with 67 goals in 143 caps, had successful surgery on Thursday as confirmed by his club LA Galaxy.
The Galaxy captain is expected to miss four to six weeks after going under the knife, meaning he should be fit in time for Euro 2016.
A club statement read: "LA Galaxy forward Robbie Keane underwent successful surgery on his right knee Thursday afternoon in Los Angeles.
"The surgery was performed by Dr. Bert R. Mandelbaum at the Santa Monica Orthopedic and Sports Medicine Group and Kerlan-Jobe Institute at Cedars-Sinai.
"The Galaxy captain is expected to miss 4-6 weeks."
Keane has already scored two goals in MLS this season and is likely to play an important role in his nation's Euro 2016 campaign, having scored five goals during the qualifying campaign.
Keane posted a photo of his knee in bandages on his official Instagram account, with the caption: "Operation done speedy recovery hopefully, back soon stronger #lagalaxy #ireland".