The trio appeared alongside presenters Alex Jones and Patrick Kielty on The One Show to announce that they had signed up for the BBC programme.
All three were stood behind a screen and called out one-by-one by Jones and Kielty.
Rutherford, 29, who was unveiled first, will arrive on the dancefloor fresh from competing in the Rio Olympic Games, where he scooped a bronze medal for the long jump. Rutherford won gold in London 2012 in the same event.
He admitted to being “absolutely terrified” about showing off his moves, saying: “I have never danced a step in my life.”
Empson, who plays Walford’s Kim Fox, said it had been “hard to keep the secret”.
The 39-year-old said: “I have been avoiding every group conversation, I have been avoiding telephone calls, it is just mad.”
Joseph, 70 - who is best known for playing Dorien Green in the popular sitcom Birds Of A Feather - said: “Strictly is an iconic show and I have always loved the glamour and the dedication and the entertainment, and this year it suddenly seemed right to take part.
“I am scared and excited and apprehensive and thrilled to be a part of this wonderful show and I will try my best and enjoy this amazing experience.”
The final three contestants complete a line-up of 15 amateur dancers including former shadow chancellor Ed Balls, Pop Idol winner Will Young and model Daisy Lowe.
Gymnast Claudia Fragapane, presenter Laura Whitmore, presenter Ore Oduba, DJ and presenter Melvin Odoom, former Eternal singer Louise Redknapp, actor Danny Mac, newsreader Naga Munchetty, reality TV’s Judge Rinder and US singer Anastacia are also contestants for the new series.
Strictly Come Dancing - The Launch Show will be broadcast on BBC One on Saturday September 3, as the 15 celebrity contestants will discover which professional dancer they will be paired with as their journey towards the famousGlitterball Trophy begins.