Semi Detached will follow a group of mature adult housemates who were hoping to have achieved more in life at their age.
Ralf Little and Stephen Tompkinson will also star in the comedy series, to be filmed in May by Hat Trick.
Parkinson will play Ellie, who shares a house with Steve (Little), Michael (Tompkinson) and Jim (to be announced), reports the British Comedy Guide.
The group are either single, divorced or separated, and are forced to live in a half-way house together, despite not sharing anything in common.
Ben Bailey Smith - also known as stand-up comedian Doc Brown - and James Lance will also star.
Meanwhile, Spy actor Darren Boyd will lead the cast of new ITV sitcom The Delivery Man.
Boyd plays a policeman who decides to become a midwife in the sitcom. A pilot episode has already been filmed.
Fay Ripley, Alex Macqueen, Dominic Coleman, Aisling Bea and Holli Dempsey will also play recurring roles.
Darren Boyd currently voices the lead character in new ITV4 comedy Warren United, which debuts tonight (April 22).