Womack, who plays Ronnie Mitchell in EastEnders, did not appear on the shortlist of nominees. The eventual winner was her co-star Jessie Wallace for her portrayal of Queen Vic landlady Kat Moon.
Coronation Street star Marsh sympathised with Womack over her recent admission that she was leaving the BBC soap after being left exhausted by her alter ego's storylines.
"I can relate to that," she wrote in her latest new magazine column. "Although they're the sort of plots I love, it is hard going. It must be especially hard for Sam as she's had one harrowing storyline after another."
She continued: "She's a fantastic actress and although Jessie Wallace was a deserved winner of the 'Best Actress' award at The British Soap Awards, I think it was an oversight that Sam wasn't even nominated."
Marsh, who is currently on maternity leave, is due to return to her role as Weatherfield's Michelle Connor in September.
Read the full story in this week's new! magazine - out today.
> Kym Marsh "annoyed" by 'Enders award focus