The US comedian stepped down from The Ellen DeGeneres Show in May 2022
The actress and disability rights campaigner is a vocal opponent of assisted dying.
Comedians Rob Beckett and Romesh Ranganathan hosted the ceremony in central London
It is not yet known whether Netherlands entrant Joost Klein will perform.
The Oscar-winning actor recently denied new allegations of inappropriate behaviour from men in a Channel 4 documentary.
The couple tied the knot in a ceremony in New York in 2018
The third season of the hit show will premiere on June 27 on Disney+ in the UK.