Soap insiders recently hinted that the surprise was in store for Lloyd (Craig Charles), and the story has now been confirmed on the official ITV Coronation Street website.
Lloyd becomes aware of his estranged offspring when he bumps into Mandy, an old flame, who reveals the existence of Jenna, his grown-up daughter.
Mandy - portrayed by Pamela Nomvete (EastEnders) - becomes a cook at the Rovers, while Jenna - played by Kriss Bohn (Law and Order UK) - works at the local hospital.
Producer Phil Collinson said: "The story allows us to establish two terrific actresses alongside Craig Charles and create an instant 'new' family for Lloyd.
"Mandy is a warm and big-hearted character who has seen a lot of life and is always ready to dispense common-sense advice and wisdom.
"Jenna is a clever, educated young woman, whose life will be turned upside down as she struggles to come to accept Lloyd as her real father."
Charles returned to the soap earlier this month after an extended break, filming the new series of sci-fi sitcom Red Dwarf in the process.
Charles has said that now the break is over he is committed to the soap for the "foreseeable future".