The Royle Family actress will play Collins's character Stella Price's mum Gloria, who arrives in Weatherfield this September.
Collins told OK of the casting: "What better mum could you have than Sue Johnston? I'm so excited! She is such a cool lady."
The former EastEnders actress, who recently extended her Corrie contract for a further year, added that she expects the Rovers Return to become "very matriarchal".
Following the news that Stella is soon to discover Karl and Sunita's affair, it is unlikely that the Rovers Return will be occupied by any men for the foreseeable future.
Johnston, who was cast in early April, has had her opening storyline changed by writers after her arrival was delayed due to illness.
Gloria Price was described by as "feisty", "domineering", "overbearing" and "terrifying" by producer Phil Collinson at the time of the original cast announcement.