Girgensons participated at the 2012 World Junior Ice Hockey Championships as a member of the Latvian junior team and at the 2010 IIHF World U18 Championships. He made his senior national team debut in 2013 World Championships against the United States and scored his first international goal against Slovakia. He also was suspended for one game for spearing Branislav Mezei in the first period of the match in retaliation for an earlier hit.