There were a number of actors/actresses who played more than one person (as if we didn't notice). There are probably more besides these, especially extra kids and townspeople.

Hersha Parady: Alice Garvey, Eliza Ann (Quiner) Ingalls
Leslie Landon: Etta Plumb, Kate, Pam, Leslie
Matthew Laborteaux: Albert Ingalls, young Charles Ingalls
Ike Eisenmann: Erich Schiller, Vicktor Pyatakov
John Alderson: Henry Holbrook, Turnbull
William Schallert: Snell, Dean Harmon
Carl Pitti: Carl, man, Silas, customer, rider, wagon driver, dance caller, Len
Ketty Lester: Hester-Sue Terhune, Janie Kagan
Ruth Foster: Mrs. Foster, woman, Aunt Susanne
Kyle Richards: Alicia Sanderson Edwards, Samantha Harper
Billy Barty: Lou Bates, Owen
Royal Dano: Harold, Mr. Webb
Ricky Segall: boy,Todd
Ivan Bonar: Mr. Case, Dr. Mayes
Olan Soule: Mr. McGinnis, ticket agent
E.J. Andre: Jed Cooper, Matthew Simms, Zachariah, St. Peter
Bryce Berg: Jason, boy
Michael Pataki: Stanley Novack, Quinn
Richard Jaeckel: Irv Hartwig, Murphy

Katy Kurtzman:

Anna Gillberg - "The Music Box" (Season 3)
Young Caroline - "I Remember, I Remember" (Season 4)

Oh yes, Cat. I knew there would be more. Good eye!

It's mind-blowing how many they had. (Of course, we didn't notice).
:wave: