Frank Crowther, 87, was found near the body of his wife Winifred at their home in Sutton, Surrey, on Thursday.
Police are not looking for anyone else in connection with the incident.
Officers were called at about 6:30pm to an address in Lumley Road where they discovered the body of Mrs Crowther, 83. She was pronounced dead at the scene.
A Metropolitan Police spokesman said: "A post-mortem gave cause of death as multiple stab wounds.
"She has now been formally identified as Winifred Crowther, 83, of that address.
"An 87-year-old man was found unconscious at the scene. He was taken to a south London hospital where his condition is described as critical."
Officers from the Homicide and Serious Crime Command are investigating.
Leslie Crowther died in 1996 aged 63. He earned his first break on television as part of a zany comedy duo with Peter Glaze on the children's programme Crackerjack.
He became a household name when he went on to host popular television game show The Price Is Right.