Samu Manoa earned his first cap on November 27, 2010, against Georgia. His first try for the Eagles came in a win against Russia on November 23, 2013. Domestically, Samu played for San Francisco Golden Gate R.F.C. before being contracted to play for the Northampton Saints of the Aviva Premiership.
In his 3 years with the Saints, Samu has become a household name earning multiple honors and awards including being named to the Premiership Dream Team for the 2011-12 season, two consecutive Saints Supporters' Player of the Season (2012-13, 2013-14) awards, and the Saints Players' Player of the Season award for 2012-13 season.
In 2013, Samu become one of only 3 Americans to be invited and play for the Barbarians, an invitational team comprising of the top rugby talent around from the world. In that same match for the Barbarians, he also became one of very few Americans to lineup against the British & Irish Lions, a storied team consisting of elite talent from England, Ireland, Scotland, and Wales. Additionally, he was also named to the shortlist for the Premiership Player of the 2013-14 season.