The $500 million deal, which includes the purchase of a high-performance radar system, is also seen as a nod to improvements in Indonesia's human rights record, The Wall Street Journal reported Monday.
U.S. Defense Secretary Chuck Hagel announced Indonesia had gotten a green light to purchase the advanced Apache aircraft and the Longbow Fire Control Radar during an official visit to Jakarta.
A U.S. defense official said Indonesia would use the helicopters in counter-piracy missions and other military operations.
Washington is working to expand military ties with countries around Asia.
Indonesia had been sanctioned by the United States over allegations of human rights abuses. President George W. Bush had dropped restrictions of sales of military equipment to the country and restrictions on training the Indonesian military were dropped in 2010.
In a statement, Hagel praised the country's efforts to "improve transparency and the protection of human rights."
Hagel said further progress on "this critical issue" would lead to "even more momentum in our defense relationship."