The show's producer announced the news on This Morning today (April 2), promising that Johnston's character Gloria will cause a stir on the cobbles.
Collinson commented: "I'm very excited to be able to tell you that Sue Johnston is going to be joining the Coronation Street cast. She starts recording with us in a couple of weeks, and she'll be on screen in June.
"She's going to play Gloria Price - Stella's mum, and Leanne and Eva's grandma. A very vivid, brilliant character, I think - already from what I'm reading in the scripts.
"She's feisty, brilliant - she comes over from Spain, where she's been running a bar, so she's perma-tanned! She's a terrifying, domineering, overbearing mother, so there's going to be sparks flying."
Gloria's debut episode will see her arrive in Weatherfield unannounced, telling Stella (Michelle Collins) that she only plans to stay for a short time. However, she is still around months later - leaving Stella suspicious over what her mum has been up to abroad and why she isn't returning.
A Coronation Street statement teased: "It soon becomes clear that Gloria has been economical with the truth and the sparks fly between her and her daughter.
"And the ladies of Weatherfield soon discover that they will have to keep an eye on their men, as she sets her sights on Dennis and Lewis.
"Larger than life, ballsy and outspoken, Gloria will be in the great tradition of strong Weatherfield women who don't take no for an answer and live life to the full."
Johnston's extensive CV includes her roles as Brookside's Sheila Grant and The Royle Family's Barbara Royle.
> Coronation Street to cast Stella Price's mother
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