Len will be absent from the BBC One show for a week to focus on Dancing With The Stars, the US version of the series which Hollywood star Jennifer won in 2010.
The actress is best known for her starring role in the 1987 dance classic, Dirty Dancing, with Patrick Swayze.
Jennifer achieved consistently high scores on the show when she was a contestant alongside her professional dance partner, Derek Hough.
The actress said of her guest judging role: "I am delighted to be involved. I so look forward to making the pilgrimage to the birthplace of the greatest dance show, the mecca of spray tans and tangos, and to sit in for the great and pernickety Len Goodman."
Jennifer will waltz onto UK screens on November 5 and 6, joining Craig Revel Horwood, Alesha Dixon and Bruno Tonioli until Len returns.
It is hoped she will even perform a routine of her own with one of Strictly's male professionals, to show the current contestants how it's done.