Fontaine is a free agent after leaving Bristol City earlier this summer following an eight-year spell at Ashton Gate.
The left-sided centre back has a wealth of experience at Championship level and was a member of the side that just missed out on promotion to the Premier League in 2008 when they lost the Championship play-off final to Hull.
The former Fulham man has made over 300 appearances in his career and came close to joining Southampton in the summer of 2011, but ended up staying at Bristol City.
The 28-year-old has now linked up with Bolton for training so that Dougie Freedman can cast an eye over him at close quarters.
If Fontaine impresses in training he could be offered a deal at the Reebok Stadium with Freedman keen to bolster his defensive options.