Steffon is an English professional rugby union player who currently plays for French club Stade Niçois. Born in San Fernando, Trinidad and Tobago in 1985,  Armitage grew up in the south of France, where he and his brothers played for Rugby Nice Côte d’Azur Université-Racing.
Armitage began his professional rugby career at Saracens, before signing for London Irish in 2006. Armitage started for London Irish in the 2009 Premiership final against Leicester Tigers.

At international level, Armitage was a member of the England Saxons squad that won the 2008 Churchill Cup. On 1 July 2008 he was selected to represent the England Saxons again. Armitage was called up for the England elite squad ahead of the 2009 Six Nations Championship to replace the injured Lewis Moody, making his full international debut in England’s 36–11 win against Italy in the opening game.He started both matches in England’s drawn two test series against Argentina in June 2009. Armitage went on to win two further England caps in the 2010 Six Nations, coming off the bench in England’s wins over Wales and Italy.