The 26-year-old has been hugely impressive since arriving at Carrow Road in 2010 despite last season being disrupted by injury.
Chelsea are in need of cover for first choice keeper Petr Cech following the release of both Hilario and Ross Turnbull - with highly rated youngster Thibaut Courtois again loaned out to Atletico Madrid.
Ruddy started his career with Cambridge United before a high-profile move saw him sign for Everton in 2005.
However, he made just one appearance in five years for the Merseyside club and was loaned out to several clubs including Stockport (twice), Crewe and Motherwell.
And having failed to make the breakthrough at Goodison Park, Ruddy opted for a move to Norwich in July 2010.