Listed alphabetically by first name of Actor. Thanks to Suzy for this comprehensive list. Also thanks to Rena for the Actor images.

Alastair Hunter -Mr Carlton -The Distant Voice	Alethea Charlton -Phyllis Wetherby -The Helping Hand	Alphonse Kaminski -Small Boy -Walk In The Woods	Ambrosine Phillpotts -Lady Martha Carne -Debt of Honour	Andrew Sweeney -Small boy -The Debt
Ann Way -Mrs Buckley -Barney	Anthony Andrews -Lord Beck -The Awakening	Anthony Woodruff -Bricklebank -Fly Away Home	Arthur Hewlett -Old man -A Day In The Sun	Arthur Lambert -Policeman -Gypsy

Arthur English - Slugger Jones - 38 episodes (Didn't appear in The Challenge)

Barbara Keogh -Apple woman -Miss Him When He's Gone	Basil Henson -Arthur Maddocks(Dora's father) -Dora, Fly Away Home	Bernadette Milnes -Noreen -Moonstone	Bernard Lee -Woodman -Walk In The Woods	Bert Palmer -Tom Platt -One White Foot Charley, The Innocents
Beryl Cooke -Miss Patience (Headmistress) -Out of the Blue Horse,The Bridge Builder, Uncle Joe	Betty Turner -Emily Derwent -Treasure Hunt	Also Mrs Barrett -The Four Legged hat	Bill Dean -Mr Clegg -The Dream	Brenda Cowling -Lady Caroline Beck -The Awakening
Brian Osborne -Tyler -The Innocents	Bryan Sweeney -Gip Willens -The Charity Horse, Know-All's Nag, Stryker's Good Deed	Celia Hewitt -Anna Holmes(Callie's mother) -Moonstone	Charles Lamb -Old Man In Cafe -Someone, Somewhere	Charles Pemberton -Police Sergeant -Uncle Joe

Christian Rodska - Ron Stryker - 38 episodes (Didn't appear in Out of the Blue Horse)

Chloe Franks -Angela -Uncle Joe	Christopher Coll -George Platt -One White Foot Charley	Clare Kelly -Katherine Ross (Steve's mum) -Someone, Somewhere, The Debt	Clifford Rose -Mr Dockerty -Poor Bald Head	Colin Bell -Johnnie Clegg -The Dream
Colin Douglas -Matt -The Innocents	Colin Rix -Vet -Dora, A Day In The Sun	Daphne Oxenford -Secretary -Poor Bald Head	David Hemmings -Uncle Joe Rimmington -Uncle Joe	David Richardson -Groom -Steve
David Swift -Mr Bendiger -Poor Bald Head	David Wilkinson -Hooligan -Hazel	Dorothea Rundle -Agnes Derwent -Treasure Hunt	Dorothy Reynolds -Prudence Maddocks(Dora's mother) -Dora,Fly Away Home	Edward Underdown -Matthew -Steve

Desmond Llewelyn-Colonel Geoffrey Maddocks-35 episodes(Didn't appear in Barney, The Challenge,The Letter,The Helping hand)

Elaine Donnelly -Wendy Bendiger -Poor Bald Head,The Prize	Freda Jeffries -Cauliflower Woman -Miss Him When He's Gone	Frederick Treves -Sam Lockwood -Barney,The Dream,The Challenge,The Letter	Fulton Mackay -Mr Wilmot the lock-keeper -Someone, Somewhere	Garfield Morgan -Brian Donnelly -Hazel
Garth Watkins -Parkinson -The Letter	Geoffrey Morris -Vet -The Prize,The Distant Voice,The Dream,The Helping Hand,Hazel,Walk In The Woods	George Malpas -Mr Plum -The Letter	George Waring -Bert(Policeman) -Moonstone, Someone,Somewhere	Geraldine Newman -Janet Draper -A Present for Sandy

Gillian Blake-Dora Maddocks-Appeared in all 39 episodes

Gillian Bailey -Callie Holmes -Steve,One White Foot Charley,Moonstone,Out of the Blue Horse	Godfrey James -Willie -The Innocents	Gorden Kaye -Man with Court Order -The Dream	Greg Powell -3rd man -Steve	Gretchen Franklin -Mrs Porter -The Awakening,Fly Away Home,Hazel
Harold Goodwin -Bill -The Innocents	Harry Littlewood -Bargee -Someone, Somewhere	Harry Markham -Hercule's owner -Someone, Somewhere	Howard Goorney -Reuben Kellet -Gypsy	Ivan Beavis -Liverpool Policeman -Someone, Somewhere,The Debt
James Ottaway -Bill Chadwick -Rain On Friday	Jack Le White -Weighman -Poor Bald Head	Jack Woolgar -Seth Draper -A Present for Sandy	Jane Hutcheson -Judy -Someone, Somewhere	Janet Hargreaves -Lady Millicent Longchild -The Debt
Jill Summers -Mrs Ginwood -The Letter	Jean Lockhart -Shopkeeper -Fly Away Home	Jo Warne -Onion Woman -Miss Him When He's Gone	Joe Ritchie -Bert -The Debt	John Barrard -Pilkington -The Letter
John Barrett -Ernie Perkins -Poor Bald Head	John Barrie -Ed Foley -Miss Him When He's Gone	John Cater -Clem Barrett -The Four Legged Hat	John Lyons -Photographer -The Charity Horse	John Stratton -Arnold Berwick -Out of the Blue Horse
John Swindells -Policeman -Stryker's Good Deed	Kareen Hofsass -Little girl -Birthday at Follyfoot	Kathleen Michael -Mrs Wilmot -Someone, Somewhere	Kathleen St. John -Old Lady -A Present for Sandy	Kathy Staff(1) -Woman -One White Foot Charley
Kathy Staff(2) -Woman -The Letter	Kay Gallie -George Platt's wife -One White Foot Charley	Keith Buckley -Geoff Shaw -The Hundred Pound Horse	Keith James -Shopkeeper -One White Foot Charley	Ken Watson -Charlie -The Innocents
Larry Noble -Tanner -Treasure Hunt	Len Jones -Willy Willens -The Charity Horse, Know-All's Nag	Leon Vitali -Brian Foley -Miss Him When He's Gone	Lesley Roach -Angie Buckley -Barney	Leslie Dwyer -Mr Wimble -The Debt
Leslie Schofield -2nd Policeman -Someone, Somewhere	Lewis Wilson -Ambulance man -A Present for Sandy	Leyland Vincent -Policeman -Walk In The Woods	Lynne Frederick -Tina -The Bridge Builder, Uncle Joe	Lynne Perrie -Woman -Stryker's Good Deed
Maggie Flint -Mrs Widgeon (landlady) -The Debt	Margaret Boyd -Steve's Grandmother -A Day In The Sun	Marc Granger -Tim Shaw -The Hundred Pound Horse	Margery Mason -Mrs Willens -The Charity Horse, Know-All's Nag	Maxine Barrie -Nurse -Stryker's Good Deed
Michael Collins -Garage Owner -The Debt	Mollie Maureen -Mrs Padgett -The Distant Voice	Neil Hallett -Mr Whitaker -Uncle Joe	Nigel Crewe -Chip Lockwood -Barney, The Dream, The Challenge, The Letter	Norma Shebbeare -Minnie Foley -Miss Him When He's Gone
Norman Atkyns -Mr Buckley -Barney	Norman Mitchell -Policeman -The Dream	Pam St. Clement -Cafe Assistant -Someone, Somewhere	Pamela Alan -Dorothy Corbett -Hazel	Paul Ambrose -Jackie -Uncle Joe
Paul Frith -Young Boy -The Standstill Horse	Paul Guess -Lewis Hammond -Dora, Steve, Shadow, One White Foot Charley,The Standstill Horse	Paul Luty -Groom -Dora	Paul Rosebury -Mick -Walk In The Woods	Paul Whitsun-Jones -Man (Lollipop's owner) -The Helping Hand
Peter Porteous -Wally -The Innocents	Peter Schofield -Van Driver -Fly Away Home	Peter Whitbread -Auctioneer -The Four Legged Hat	Peter Copley -Sir John -The Bridge Builder	Petra Markham -Ginny Tuckwood -The Standstill Horse
Phil Woods -Ben -The Innocents	Ralph Lawton -Doctor at Gymkhana -The Awakening	Ray Mort -Policeman -Miss Him When He's Gone	Ray Witch -Shopkeeper -The Four Legged Hat	Raymond Adamson -Major Lewis -The Challenge
Reginald Barratt -Unnamed -The Standstill Horse	Richard Beaumont -Gavin Foley -Miss Him When He's Gone	Richard Goolden -Mr Mallet -Mr She-Knows	Rio Fanning -Reporter -The Charity Horse	Ron Pember -Picket 1 -The Innocents
Ron Welling -Horse Owner -The Four Legged Hat	Ronald Leigh-Hunt -Bernard Fox -The Helping Hand	Rosamond Burne -Florist -Fly Away Home	Rosamond Greenwood -Aunt Millie -A day In The Sun	Ruth Holden -Mrs Dickerson -The Letter
Sadie Eddon -Stunt woman -Barney	Sam Kydd -Bookmaker -Shadow	Sammy Sharples -unnamed -Stryker's Good deed	Sheila Fay -Judy's Mother -Someone, Somewhere	Shelagh Fraser -Vera Berwick -Out of the Blue Horse
Simon Thompson -Sandy Draper -A Present For Sandy	Simon Roebuck -Simon -The Bridge Builder	Stan Jay -Linnett -The Dream	Stephen Bent -Noreen's partner -Moonstone	Sue Cornell -Jacqueline -The Bridge Builder

Steven Leslie Hodson-Steve Ross-Appeared in all 39 episodes

Ted Carroll -Man -Moonstone, The Letter	Ted Carroll -Man -The Letter	Ted Carroll -Horse owner -A Day In The Sun	Terence Davies -Davey -The Innocents	Terence de Marney -Groom -Dora
Terry Cantor -Mr.Simpkin -Stryker's Good Deed	Tim Pearce -Picket 2 -The Innocents	Tommy Boyle -Gypsy -Gypsy	Tommy Godfrey -Mr Stryker (Ron's father) -Mr.She-Knows	Tony Steedman -Mr Tuckwood -The Standstill Horse
Tracy Eddon -Lisa Pilkington -The Letter	Valerie Holliman -Cleo -Family of Strangers	Veronica Quilligan -Hazel Donnelly -Hazel, Walk In The Woods	Virginia Denham -Isobel Mathews -Shadow	Wallace Campbell -Vet -One White Foot Charley
Walter Horsbrugh -Doctor -Treasure Hunt, The Awakening	Walter Randall -Tinker -Walk In The Woods	Walter Sparrow -Amos Kellet -Gypsy	William Mervyn -Squire Mathews -Dora, Shadow	Wolfe Morris -Parkes -Debt of Honour