Three years on, actors Anne Reid, Derek Jacobi, Nicola Walker and Sarah Lancashire are seen reunited in set photos with Timothy West, who is making his own return to the series, which is produced by Lookout Point, the makers of Gentleman Jack.
Crews working on the show were spotted filming in Elland just last week.
Sally Wainwright, creator and writer, said: “Yet again the entire Last Tango cast has proved to be so wonderful together, so uplifting, heart-warming, touching and funny, as they explore Celia and Alan’s relationship further, under the brilliant breath of fresh air that Gareth Bryn’s direction has given them.”
Alan (Derek Jacobi) and Celia (Anne Reid) are now seven years into their marriage but, having moved into a desirable bungalow with views across the Calder Valley, they are not seeing eye to eye.
Differing politics are a source of tension, while Alan’s new supermarket job brings an unexpected challenge in the form of a "wild local lad", and at Far Slack Farm, Gillian (Nicola Walker) faces trouble with a giraffe.
Meanwhile John (Tony Gardner) is back on the scene, and Caroline (Sarah Lancashire) finds herself entangled in an emotional debacle with someone at work.
Into all of this comes Alan’s brother Ted (Timothy West) on holiday from New Zealand.
But it turns out he’s only bought a one-way ticket - and he hasn’t come alone.
Also returning for the new series are: Ronni Ancona as Judith, Josh Bolt as Raff, Dean Smith as William, Louis Greatorex as Lawrence, Paul Copley as Harry, Katherine Rose Morley as Ellie, Felix Johnson as Angus, and Rachel Leskovac as PC Cheryl.
Caroline’s daughter Flora, now five years old, will be played by Issacah June Zaman Hatzer, with Calamity, now age seven, played by Tilly Kaye.
Joining the cast this series will be Lu Corfield (Sex Education, Clink), Anna Leong Brophy (NightWatch Man, EastEnders), Noorul Choudhury (Ackley Bridge), Liam McCheyne (The Bay, Coronation Street), television newcomer Catherine Campion, Sophie McIntosh (Brave New World, Shortland Street), Rick S Carr (Brassic, Ackley Bridge) and Buckso Dhillon-Woolleyy (Aladdin, Unforgotten).
Faith Penhale, executive producer for Lookout Point, said: “It’s been an absolute pleasure to bring the Tango team back together and watch them work their magic.
"Sally’s scripts are as brilliant as ever - warm and funny and very real - and our exceptional cast make it look easy.
"I can’t wait to give the fans four more episodes of this very special drama which they rightly love so much.”
Ben Irving, executive producer for the BBC, added: “Last Tango In Halifax is one of our most beloved dramas and we couldn’t be happier to be bringing Sally Wainwright’s phenomenal characters back to BBC One next year.”
The series is written by Sally Wainwright (Gentleman Jack, Happy Valley), directed by Gareth Bryn (Hidden, Hinterland) and produced by Ken Horn (Line of Duty, The Moorside).
Executive producers are Faith Penhale and Laura Lankester for Lookout Point, Ben Irving for the BBC, and Sally Wainwright. The series will be distributed internationally by BBC Studios.
Last Tango In Halifax will return in 2020 after previously running for three series and a two-episode Christmas special, with each run averaging more than seven million viewers. It was last on screens in 2016.