The Hayley Cropper actress is taking a two-month break from filming to appear in Black Roses at Manchester's Royal Exchange.
Black Roses is about the murder of student Sophie Lancaster. Hesmondhalgh has been involved with the Sophie Lancaster Foundation since 2010.
She told BBC Breakfast: "It's quite well known in Corrie, my involvement with the Sophie Lancaster Foundation.
"So when the play came up, they understood how important it was to me and so they went all-out to give me the time off to do it, so I'm really grateful to them.
"I'm going to be off now until the end of September, rehearsing and performing the play."
Speaking about her Corrie character Hayley's recent love triangle storyline with Roy and Mary, the star admitted that she was worried about the threat to her on-screen marriage.
The 42-year-old said: "I did not enjoy it! Of course I didn't enjoy it! We've sorted it out now, though; in true Corrie style it took one episode to bury the hatchet and sort it all out!"