He leaves the club with immediate effect and with director of rugby Jim Mallinder wishing him the best for the future.
"Euan is a big personality and has helped the club become competitive again at the top end of the Premiership and in Europe. He has played well for us and we have enjoyed having him here at Franklin's Gardens and we wish him all the best for the future."
Murray helped Scotland to beat South Africa and Samoa during last month's international series and played for Northampton in their two Heineken Cup matches this season, against Castres Olympique and Edinburgh.
"I've enjoyed playing at Franklin's Gardens in front of its great supporters and I will take a lot of happy memories with me," said Murray.