Indeed. Of course, the inherent nature of the show meant actors from the movies couldn't normally reprise their roles (since they'd be decades older than the characters are supposed to be in the episodes); Harrison's appearance is possible only because his segments take place in 1950, and have Indy reminiscing about his earlier days, thus making most of the show a long flashback. Most of the episodes actually followed this pattern in the show's original form, though it was a modern-day, 90-something Indy played by George Hall and not Indy in his 50s played by Harrison Ford.
There
are a tiny number of characters from the movies portrayed in the show, though, just usually not by the same actors. Obviously Indy is in all of them (no, really?
), and Henry Jones, Sr. is also in several of them. Indiana (the dog) also appears briefly. There were also plans to show Belloq and (finally!) Abner Ravenwood - scripts were written for their episodes, but the series was cancelled before they were produced.
However, there are actually several
actors from the movies who appear in the series, just playing different
characters. At least eleven actors have played more than one role in the overall franchise; of these, at least seven are people who each played one or more characters in the movies, and one more character in the TV show:
Anthony Chinn
Paul Freeman
William Hootkins
Wolf Kahler
Kevork Malikyan
Roshan Seth
Vic Tablian
(The other actors appearing in multiple roles include three people who appear in multiple roles in just the movies, and one who appears in multiple roles in just the TV show. The last guy on the list above, Vic Tablian, actually has
two roles in the movies - both in the same movie, actually - plus a third character in the TV show.)