The actress - best known for roles in Doc Martin, Tenko and Waiting for God - has been cast in the part of Roy Cropper's mother Sylvie on the ITV1 soap.
Writing on Twitter yesterday evening, Andrew Lancel, who plays businessman Frank Foster, confirmed that Cole had made her debut in the programme.
He told his online followers: "Long day but with lovely people. The legendary Stephanie Cole started today."
Sylvie has been billed as a woman with an outspoken attitude and she is expected to quickly make her mark on the cobbles following her arrival.
The newcomer's debut scenes are due to air in April.