As announced earlier this month, Waugh is to play the wife of a serial killer in the five-part series, which airs on BBC Two later this year.
Bronagh recently caught up with Digital Spy for a chat about her new project and what's coming up for her Chester character Cheryl Brady.
How are you feeling about your new BBC project The Fall?
"I'm so excited and thrilled - I keep having to pinch myself! Every now and again I'll be sitting on set thinking, 'I can't believe I'm doing this'. It's such a fantastic role and it's so different from Cheryl and other parts that I've done.
"I'm so glad that they trust me enough to do this. They've really put a lot of faith in me to be able to handle such a big role. I just feel really honoured."
How's the filming going?
"It's going really, really well - we're about halfway through filming it now. It's a tough schedule, much the same as Hollyoaks, but it's so fantastic.
"Until this week, I'd been going back and forth - doing a couple of days here in Belfast and then a couple of days at Hollyoaks. But I'm in Belfast for a week now, so it feels nice to really get my teeth into it. We're doing some of the meatier scenes at the moment and it's just brilliant."
What can you tell us about the storyline of The Fall?
"It's a psychological thriller about a serial killer on the loose in Belfast. He's being pursued by the chief of police, played by Gillian Anderson. My character Sally-Ann is the wife of the killer. She's a neo-natal nurse and is completely unsuspecting about what's going on - she has no idea!
"The whole drama is about the web of lies, how close the killer gets to his secret being revealed, and whether he'll get away with it or not. It's gripping - the script is a real page-turner with wonderful writing from Allan Cubitt."
How do you feel about working with Gillian Anderson?
"She is just wonderful. We don't have any scenes together, but I met her when we did the first read-through. She was sitting opposite me, and I was just in complete awe of her!
"Gillian is really beautiful and striking, but also just an absolutely wonderful actress. She makes every line she says sound so fresh and so new. It feels like great training being able to watch her work."
Your former Hollyoaks co-star Gerard McCarthy is also part of the cast, isn't he?
"Yes, and it's lovely to be back with Gerard. He's playing a solicitor, which is quite separate to my storyline with Sally-Ann and her husband, but it's lovely to be working on another project with him. He looks so different to how I remember him - he's all grown up now!"
How supportive have Hollyoaks been over this project?
"They've all been so lovely. I told our boss Emma first, and she's been really supportive. She's really trusted me to do this, as she knows that I will work really hard to give both shows equal attention. There's not many other bosses on a continuing drama who would allow someone to go off and do this.
"The rest of the cast have been fantastic as well. I think that's what's really lovely about Hollyoaks - it's like a really supportive family. Kieron [Richardson] is my best friend and he's just been really lovely about it - he was so pleased for me. It's the same with Emmett [Scanlan] and everyone else as well."
When it comes to your Hollyoaks storylines, we know that new character Walker will soon be making an impact on Cheryl and Brendan's lives. What can we expect from him?
"Walker is a very interesting character and he's very mysterious. Everything's very much under wraps with his character and we're keeping his storyline a secret. In actual fact, I discussed it with Neil who plays Walker and I said, 'I don't want to know too much!'
"Sometimes it's better to just act with what you know and what you're given. But Neil is just wonderful and it's been really nice doing scenes with him, Emmett and Andrew Still."
Walker catches Cheryl's eye when he joins the village, doesn't he?
"Cheryl and Walker have a really interesting and mysterious kind of magnetism towards each other. It's quite weird, because a lot of people don't take Cheryl that seriously. So it's a case of: will it go anywhere, what does he want, why is he there? A lot of questions are raised and I really hope that I get to work with Neil more."
Is it true that Cheryl has quite a strong reaction when Joel is stabbed next week?
"Yes, for me, next week's episodes have been my first chance this year to get my teeth into something again. Cheryl has very much taken Joel under her wing because he's staying at her house. She knows that he's working with Brendan quite closely and that worries her. As much as Cheryl loves her brother, she worries about his tendency to go to the dark side and she doesn't want him to take Joel with him.
"So when Joel gets stabbed, it's incredibly upsetting for Cheryl. She worries about how it's come about and the involvement of people that she knows. She takes it really hard, and it really shakes things up within the family dynamics and the club dynamics. Next week's episodes are really good as everything hots up, so hopefully everyone will tune in for them."
Finally, where do you stand on the 'Stug' vs 'Stendan' debate?
"It's a really difficult one! Brendan is my brother on the show, but I think him and Ste are really damaging towards each other. At the same time, I really do believe that Brendan loves Ste and I think there will always be an affinity between them - it's just whether it's healthy for them to be together or not. I think they're like magnets and they will always get drawn back towards each other.
"I've been watching the episodes this week and I think Doug and Ste are really good together. They're really cute and funny at some points, but at other points it's heartbreaking - my heart melts for Doug!
"I'm really torn, because I wonder whether 'Stug' will be healthier than 'Stendan', but I've got that naughty little thought of, 'It'd be really good to see what would happen between Ste and Brendan', or, 'Maybe Brendan could change his ways'. As Brendan is my brother, I always want to see him in the best light!"
> 'Hollyoaks' star Bronagh Waugh lands BBC thriller part
> 'Hollyoaks' Kieron Richardson: 'Bronagh's new role is amazing'
> Read more 'Hollyoaks' spoilers and news
Hollyoaks airs weeknights at 6.30pm on Channel 4. The Fall will air on BBC Two in September.