Rowan, 60, and Sunetra, 54, initially split in 2014, but will receive their decree nisi to formally end their marriage.
The Mr Bean and Blackadder star has since entered into a relationship with actress Louise Ford, who at 32 is almost 30 years his junior.
Rowan and Sunetra met in the late 1980s, when she was working as a make-up artist at the BBC, and were married in February 1990. They have two children together - son Ben, and daughter Lily, who is also an actress and has featured in films alongside her father.
The couple were building an £11 million home together when they broke up, and have since moved into separate London residences.
Rowan and his new girlfriend, actress and comedienne Louise Ford, pictured in April 2015
Rowan's relationship with new partner Louise blossomed after the pair appeared together in the West End in the comic play Quartermaine's Terms, during which time he professed a love for roles in theatre environments.
'I'd be amazed if this was a one-off,' he revealed in an interview with the Telegraph, prior to the opening of the show. 'To an extent it depends how it goes but I do like theatre, I feel comfortable in the medium. In the end, there's nothing like it, as long as I can find roles I feel I could play.'
The actor is notoriously private about his personal life, and has not spoken out about his time with Louise, although it is estimated that they have been dating for around 18 months.
Neither Rowan or Sunetra have yet released a statement on their split.