Harrington missed the cut in three out of the four majors in 2010. In an inconsistent season, he had five top-10s on the PGA Tour, but also missed six cuts. He was a controversial wild-card pick by European captain Colin Montgomerie for the 2010 Ryder Cup. He won two matches and lost two matches as Europe regained the Ryder Cup. It was his sixth Ryder Cup and fourth time being on the winning team. He won his first tournament in two years at the Iskandar Johor Open in Malaysia on the Asian Tour. He finished the year ranked 25th in the world.