Christian Day (born 24 June 1983) is a rugby union player for Northampton Saints in the Aviva Premiership, who's position of choice is a lock.
Day previously played all of his professional career at Sale except for a short term contract at French giants Stade Français. In the 2005–2006 season, Day played as a replacement in the final as Sale Sharks won their first ever Premiership title.
Joining Northampton Saints back in 2003, Day has since racked up over 200 appearances for the Midlands side. In that time, Day helped Saints to lift both the Aviva Premiership and European Rugby Challenge Cup trophies in Northampton's Double Winning season of 2013/14, the lock among the replacements for both finals.
Holding the post of the Chairman of the Rugby Players' Association since 2014, Day was named Players' Player of the Season in that double winning season by his Saints peers.
Most recently Day was amongst the squad that helped Saints' second team the Northampton Wanderers clinch the 2016/17 Aviva 'A' League trophy, though was not in the side for the final against Gloucester United.