Maitland joined Glasgow Warriors in 2012, and won his first cap for Scotland at the start of the 2013 Six Nations Championship. After 3 years playing for Glasgow Warriors, Maitland moved to London Irish, and in 2016 to Saracens. During his time at Saracens he has won two Premiership titles in 2018 and 2019, scoring a try in the 2019 final. He also helped Saracens win the European Champions Cup in 2019, scoring a try in the final. He had previously missed Saracens' victory in the 2017 European Champions Cup final through injury.