Anyone in 1997 suggesting that South Park would have 23 seasons and more than 300 episodes under its belt a couple of decades later would have been called optimistic. But that's the level of success South Park has achieved. Throughout those 30o+ episodes, there has been an almost endless parade of actors in a huge variety of roles.
Like any series with the massive scope of South Park, some actors really nailed their roles while others just didn't quite click with the comedy. And it's safe to say that any character voiced by Matt Stone or Trey Parker was dead-on perfect.
10 Fell Short: George Clooney As Sparky
One of the biggest behind-the-scenes stories of South Park is the role Hollywood icon George Clooney's involvement. Reputedly, it was his early support that helped get South Park off the ground. He voiced an early one-off character, Sparky, Stan's gay dog.
It's not that Clooney necessarily did a bad job barking like a dog. But at the same time, his presence in such an innocuous role looms large over the episode. The episode, Big Gay Al's Big Gay Boat Ride, featured the first appearance of Sparky, and Big Gay Al.
9 Nailed It: Mona Marshall As Sheila Broflovski
While South Park is focused on the adventures of kids, their parents may actually be more ridiculous than them. The nonsense Randy Marsh gets caught up in is, without question, legendary. Then there's Sheila Broflovski, an incredibly pushy and overbearing lunatic.
Mona Marshall has voiced Sheila in more than 200 episodes of South Park since 2000. She has absolutely defined the character, finding new and more absurd ways to evolve Sheila as South Park has changed over the years.
8 Fell Short: Eliza Schneider As Sharon Marsh
Between 1999 and 2003, Eliza Schneider provided voices for an impressively wide range of characters. That included nailing her role as Liane Cartman as well as voicing several of the Raisins Girls, Principal Victoria, and Wendy Testaberger.
But her turn as Sharon Marsh didn't seem to click as well. Other actors were far more successful in the role, similarly to how Schneider made her mark as other characters. She was definitely a key voice during that era, just not as Sharon Marsh.
7 Nailed It: Diedrich Bader As Bat Dad
Sometimes a one-time background character makes a huge impression. This was certainly the case with Bat Dad, the king of parent brawls at Little League baseball games. Randy took it upon himself to confront Bat Dad, and take him down.
Diedrich Bader, a voice acting icon, gave Bat Dad his voice in an uncredited role. He performed terrifically, which is hilarious as one of the characters, Bader, is best known for voicing is Batman.
6 Fell Short: April Stewart As Liane Cartman
The complicated heritage of Eric Cartman shouldn't be as confusing as it is. That's largely thanks to Liane Cartman who can't seem to stop lying to her son about who his father is. As it turns out, Cartman may have the same father as his greatest enemy, Scott Tenorman.
Several actors voiced Liane over the years, with April Stewart most recently portraying the role. She does reasonably well as Liane, but she makes a much better Sharon Marsh. April nails the annoyed tone that Sharon gets in her voice when she talks to Randy almost perfectly. But unfortunately, her role as Liana Cartman didn't quite hit the mark.
5 Nailed It: Vernon Chatman As Towelie
Of all the characters who could have become a fan favorite, Towelie was definitely a long shot. This anthropomorphic, drug-addicted towel has caused nothing but problems to everyone in South Park since he arrived. But fans still love him, and a big part of that is his voice.
Towie's incredible and distinctive voice was provided by Vernon Chatman from 2001 to 2019. Without question, the character would not have been anywhere near as popular or successful without Vernon's work.
4 Fell Short: Kyle McCulloch As Richard Dawkins
For nine years, Kyle McCulloch lent his voicing talents to various characters on South Park. They ran the gamut from a Russian Terrorist to Gandalf to a Gladiator. One of his best was voicing Bono in the infamous episode, More Crap, which is one of the few episodes where neither Kyle, Cartman nor Kenny appear.
McCulloch also voiced Richard Dawkins in South Park. McCulloch did a reasonable job voicing this depiction of Dawkins, though the overall premise behind that depiction was flawed at best.
3 Nailed It: Bill Hader As Ike Broflovski
For a kid in kindergarten, Ike Broflovski goes on some serious adventures. This young Canadian is the adopted younger brother of Kyle and is incredibly smart for his age. Frankly, he's likely smarter than most of the adults on the series.
There have been several people to voice Ike over the seasons. But the one person who made the character his own was SNL alum, Bill Hader. He has also voiced other characters for South Park, but he definitely excelled at portraying Ike.
2 Fell Short: Natasha Henstridge As Ms. Ellen
Back in the good ol' days, Wendy and Stan were the hottest couple in their class. Everything was going fine until a substitute teacher named Ms. Ellen showed up. Wendy ultimately dispatched her by selling her out to the Iranians. It was a savage move, to say the least.
Ms. Ellen only made one appearance on South Park in the episode Tom's Rhinoplasty and was voiced by Natasha Henstridge. Her voice acting was okay, but there had to be a better choice. That being said, it was a pretty big coup back in those days that they got her on South Park.
1 Nailed It: Issac Hayes As Chef
In the early days of South Park, a character named Chef played an integral role in the series. He was the only person who really seemed to take an interest in guiding the boys, and was painfully honest with them almost all the time.
The late Issac Hayes voiced the character brilliantly. Reportedly, a falling out between him and the creators ended his run on South Park. They eventually killed the character off, which was the right choice as no one else could have voiced him.