The hit series follows Detective Superintendent Sandra Pullman’s (Amanda Redman) and her team of retired ex-coppers who investigate the Met’s unsolved crimes.
Laswson will play,retired Detective Inspector Steve McAllister, described as “is a bundle of energetic optimism with a tendency to get personally involved in the cases he’s working on.”
The series also stars Dennis Waterman and Alun Armstrong.
Lawson said he was “delighted to be joining Amanda, Alun and Dennis on New Tricks.
“I’ve long admired the show and love its ability to be warm, humorous and gritty simultaneously. I’m really looking forward to being part of it.”
Executive Producer Richard Burrell says: “Casting a new member of the UCOS team was always going to be an exciting challenge and we are absolutely thrilled that the brilliant Denis Lawson is joining us.
“Denis brings warmth, wit and charm to the character Steve McAllister and is a very welcome addition to the New Tricks family.”
The ninth 10-part series of New Tricks is currently filming at Pinewood Studios and on location in London for transmission on BBC One later this year.