The military says one boat deviated 150 nautical miles (280 kilometers) from its intended route and another was near the island of Makin where it went missing.
Military crews were able to drop survival kits, including water and locator beacons, on board, and then contact nearby boats to rescue survivors. Among those rescued was an 11-year-old child.
Air Commodore Shawn Sexton said being able to find survivors on both boats was a great result.
In a social media post sent before the survivors were found, the Kiribati government said it had requested New Zealand to send a search and rescue team and was grateful for their ongoing assistance during such incidents.
Located south of Hawaii, Kiribati is home to about 114,000 people and does not have its own military.