When it comes to Friends, the focus is often placed on the main group and the relationships they have. While all of those characters are superb, they wouldn't be what they are without the terrific supporting cast around them. Whether referring to the random characters that they date, family members who pop in every now and then, or coworkers they clash with, there's plenty of excellent supporting characters on this sitcom.
Over the course of the 10 seasons, there were a lot of characters that came and went, but some of made far bigger impacts than others. Certain characters make fleeting appearances in one episode, while others had huge arcs on the series, making major changes to the story with their actions.
Mr. Heckles
Mr. Heckles might not have been happy or quick to give a laugh to the group, but he did have a big impact on the show. Whether it was his grumpy one-liners or him banging on the roof when the group was making too much noise, Mr. Heckles would always make his presence known.
However, it was actually his death that brought the biggest impact to the show. Not only did the group grow closer together, but Chandler, in particular, was able to learn some valuable lessons about himself as a person.
Marcel
That's right, Ross' pet monkey is one of the most impactful supporting characters on the show, mainly because he is a monkey, which brings a lot of mischief and iconic moments to the series. He's someone that every fan instantly remembers, especially since there aren't too many pets on the show overall.
He's a character that audiences love, and the impact he has on Ross in particular is undeniable. Marcel is somebody that just brings a lot of fun to the show throughout his time onscreen, and the pain it causes Ross to let him go proves the connection he has.
Richard
When it comes to romantic relationships within the show, few connect with the fans better than Richard and Monica's. The two of them were brilliant together and there was a real feeling amongst fans that they might have ended up sticking together.
While that wasn't meant to be, Richard did have a key role to play, and few characters made a bigger impact on Monica than him. Plus, the fact he returned to the show and almost stopped Monica from getting engaged to Chandler was another major deal within the series.
Jack & Judy Geller
Jack and Judy Geller really come as a pair throughout Friends, as it is quite rare to see them without each other. Ross and Monica's parents have big roles to play on the show, as they push their children throughout the story, sometimes in a good way and others times negatively.
Judy's persistence on picking out Monica's faults is a big part of their relationship, while Jack is someone who is around to give great advice and some funny one-liners. They are always popping in and out, and their comments have a big impact on the show.
Carol
Carol has a big role to play in the early onset of Friends, but that is something that wanes as time goes on. However, while she's not around as often in later seasons - mainly being mentioned in passing rather actually appearing - she is still a hugely impactful character.
Ross' first major storyline is him getting over the fact that they have got divorced, and then that story only gets bigger when Carol becomes pregnant. This is a big storyline in the show, with Ben playing a key role in Ross' life, and all that impact comes from Carol.
Janice
When it comes to iconic supporting characters from Friends, Janice is one that most people will think about immediately. Her brilliant laugh and memorable comments to other characters help to make her stand out, and she also has a big role to play on the storylines overall.
The fact that Janice has several relationships with Chandler - as well as a brief fling with Ross - makes her impact on the series a great one. She appears several times throughout the show and always makes her mark, which is why she becomes a beloved character overall.
Frank Buffay Jr.
Phoebe's brother isn't around as long as some other supporting characters, but there is no denying that he has a huge impact on the show once he arrives. Frank Jr. is a hilarious character who quickly became a fan favorite, but his humor and funny comments aren't the reason for his big influence on the show.
Of course, Frank and his wife, Alice want to have children but they aren't able to, which is where Phoebe steps up. She carries the children for them, giving birth to triplets which ends up being one of her most memorable storylines.
Gunther
Gunther appears constantly throughout the series and because of that, it is no surprise that he is one of the most influential supporting characters. While he never gets a true main storyline with any of the characters, Gunther is constantly involved and having an impact on what is going on.
Whether it be his desire to be in a relationship with Rachel, the fact that he gives several of the main characters a job, or his hilarious one-liners. Gunther is a constant force on the show and has a big role to play throughout it.
Emily Waltham
Emily Waltham is quite a controversial character that many fans didn't like, however, there is no denying that she has a huge impact on the series overall. Emily is involved in one of the biggest romances within the show, eventually marrying Ross in London.
Her impact is undeniable, with some hilarious scenes with Ross when things begin between them. However, she then turns the tables when she wants to take Rachel out of Ross' life, and the impact of their eventual divorce and the fact that the characters all head to London for a period of time making her influence clear.
Mike Hannigan
Out of all the secondary characters, Mike really does have the biggest impact because, by the end of the series, he is actually part of the main group. He's the only supporting character in the show who is romantically involved with one of the leads, and his marriage to Phoebe is a big deal.
His character is one who massively impacts Phoebe and her storyline due to their romance. He is someone who manages to genuinely become a main character, and that is a feat within itself, as few characters were able to truly break into that tightknit group like him.