Len Goodman will take a week off next month while he works on both Strictly and the US version of the show Dancing with the Stars.
Grey triumphed on the 11th season of Dancing with the Stars, during which she partnered with Derek Hough and achieved perfect scores on multiple occasions.
"I'm delighted to be involved and can't wait to see what the contestants have got," said Grey.
"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."
The actress will appear on the November 5 edition of the programme.