Butler made his debut for the West Coast Eagles in Round 10, 2004 against Richmond, gathering 14 disposals, 5 marks and 1 goal in a 37 point win to the Eagles. He went on to play 12 games that season, including a losing elimination final against Sydney.
In 2005, he played 14 games for the club including the losing grand final against Sydney.
2006 was a much more successful seasons for Sam. He played his first game of the season in round 13 against the Western Bulldogs, picking up 22 disposals and 6 marks. He notched up a further 13 games (14 games in total for the season) and having a superb 2006 final series, in particular his performances against the Western Bulldogs in the semi final (30 disposal, 3 marks, 6 tackles) Adelaide in the preliminary final (22 disposals, 6 marks, 1 goal), as well as being part of the 2006 premiership winning team over Sydney.
In 2007, he struggled with a persistent groin injury (osteitis pubis) and was restricted in the games he played, not playing any AFL games and only playing a handful of WAFL and WAFL reserve games for Perth.
He has had a slow start to season 2008, having a modified pre-season training program due to his nagging groin injuries and played 5 games for his WAFL side Perth, playing 2 reserves games and 3 senior games. He was given a week off before making his return to the Eagles senior side against Sydney in Round 11.
Playing against Collingwood in round 20 of the 2014 season, Butler recorded 32 disposals and took 14 marks, both career highs. In the 2015 AFL Grand final, he was one of the Eagles best players during the game.