Here's a snapshot of what I think is published for the first time in October 2021 (and is usually a UK date but occasionally will be a US or Australian date). October and future months (and years) can be found on the Future Releases page. If I've missed anything or got the date wrong, do please leave a comment. I've added the translator's name where known.
• Amphlett, Rachel - The Lost Boy #3 Detective Mark Turpin
• Archer, Jeffrey - Over My Dead Body #4 Detective Chief Inspector William Warwick
• Barnes, Kerry - Trusted (ebook only)
• Beaton, M C - Agatha Raisin: Down the Hatch (with R W Green) #32 Agatha Raisin, Retired PR person, Cotswolds
• Bengtsdotter, Lina - For the Lost #3 Detective Charlie Lager - tr. tbc
• Black, Benjamin (as John Banville) - April in Spain #8 Quirke, pathologist, 1950s Dublin
• Bowen, Rhys - God Rest Ye, Royal Gentlemen #16 Lady Georgiana Rannoch ('Georgie'), 1930s Britain
• Brightwell, Emily - Mrs. Jeffries and the Midwinter Murders #40 Mrs Jeffries
• Brittany, Amanda - The Island House
• Brody, Frances - A Murder Inside #1 Nell Lewis, Prison Governor, Yorkshire, 1960s
• Buckley, Fiona - Shadow of Spain #20 Ursula Blanchard, an Elizabethan lady
• Burnet, Graeme Macrae - Case Study
• Camilleri, Andrea - Riccardino #28 Inspector Montalbano, Sicily, Italy - tr. Stephen Sartarelli
• Child, Lee - Better off Dead (with Andrew Child) #26 Jack Reacher, ex MP, USA
• Corbin, Julie - Whispers of a Scandal
• Craig, Fergus - Once Upon a Crime #1 Detective Roger LeCarre, Exeter
• Croft, Kathryn - The Other Husband
• Crouch, Julia - Mother's Helper
• Dakin, Emma - Perils in Yorkshire #3 British Book Tour Mysteries
• Davies, Abby - The Cult
• Dean, Will - Bad Apples #4 Tuva Moodyson, Sweden
• Diamond, Katerina - Trick or Treat #7 DS Imogen Grey and DS Adrian Miles
• Eldridge, Jim - Murder at the Savoy #2 Detective Chief Inspector Coburg & Sergeant Lampson
• Ellis, Joy - Fear On the Fens (ebook only) #13 DI Nikki Galena & DS Joe Easter, Greenborough
• Finlay, Caz - Traitor in the House #5 Bad Blood
• Gatland, Jack - Killing The Music (ebook only) #7 DI Declan Walsh
• Gradidge, Claire - Treachery at Hursley Park House #2 Josephine Fox
• Grebe, Camilla - The Hideout - tr. tbc
• Gudmundsson, Oskar - The Commandments - tr. Quentin Bates
• Gunnis, Emily - The Midwife's Secret
• Hall, Lisa - The Woman in the Woods
• Hancock, Anne Mette - The Corpse Flower #1 Journalist Heloise Kaldan and Police Officer Erik Schäfer - tr. tbc
• Hill, Susan - A Change of Circumstance #11 Chief Inspector Simon Serrailler, Lafferton
• Hunter, M A - Mummy's Little Secret
• Jarvis, Olly - The Genesis Inquiry #1 Ella Blake, Barrister
• Jesmond, Jane - On the Edge #1 Jen Shaw
• Kaya, Kerry - The Score (ebook only)
• Kirk, JD - Northwind #1 Robert Hoon
• Lake, Alex - Ready or Not
• Lawler, Liz - The Silent Mother
• Le Carre, John - Silverview
• Lynch, Rachel - Lying Ways #9 DI Kelly Porter, Lake District
• MacDonald, Dee - A Body at the Altar #4 Kate Palmer, Cornwall
• Mackenzie, M R - The Shadow Men #3 Anna Scavolini
• Magson, Adrian - Death at the Old Asylum #7 Inspector Lucas Rocco, Poissons-Les-Marais, 1960s
• Malliet, G M - Death in Cornwall #4 Detective Chief Inspector St Just
• Marston, Edward - Orders to Kill #9 Inspector Harvey Marmion and Sergeant Joe Keedy
• McFadyen, Ian - The Murky World of Timothy Wall #9 Inspector Steve Carmichael, Lancashire
• McGowan, Claire - I Know You
• Middleton, Ant - Cold Justice
• Mitchell, Caroline - The Midnight Man (ebook only)
• Nesser, Hakan - The Lonely Ones #4 Inspector Barbarotti - tr. tbc
• Perry, Anne - A Christmas Legacy
• Phifer, Helen - First Girl to Die (ebook only) #4 Detective Morgan Brookes
• Pine, Alex - The Killer in the Snow #2 DI James Walker, Cumbria
• Rader-Day, Lori - Death at Greenway
• Rayne, Sarah - The Murder Dance #6 Phineas Fox
• Rhodes, Kate - Devil's Table #5 DI Ben Kitto
• Ripley, Mike - Mr Campion's Wings #9 Albert Campion
• Sanderson, Lesley - Every Little Lie (ebook only)
• Scarrow, Alex - The Last Train (ebook only) #4 DCI Boyd
• Seeber, Claire - The Parents (ebook only)
• Sharp, Zoe - The Last Time She Died #1 Blake and Byron
• Sigurdardottir, Lilja - Cold as Hell - tr. Quentin Bates
• Swallow, James - Outlaw #6 Marc Dane
• Todd, Marion - Next in Line #5 DI Clare Mackay
• Tuomainen, Antti - The Rabbit Factor - tr. David Hackston
• Tursten, Helene - An Elderly Lady Must Not Be Crossed #2 Short Stories (Maud) - tr. Marlaine Delargy
• Watts, Kerry - Death Rite #1 Detective Hazel Todd
• Wood, Michael - Survivor's Guilt #8 DCI Matilda Darke
• Yakovleva, Yulia - Punishment of a Hunter #1 Investigator Vasily Zaitsev, Leningrad, 1930s - tr. tbc
• Yeo-Sun, Kwon - Lemon - tr. Janet Hong