How the Best TV Shows Build Supporting Characters Audiences Love

Not every character needs to be the protagonist. The best shows understand that supporting characters are the foundation of a great story — and they build them with care.

Think about your favourite TV show. Chances are, you didn't just fall in love with the main character — you fell in love with the ensemble. The quirky best friend. The gruff mentor. The comic relief who breaks the tension at exactly the right moment. Supporting characters make a show's world feel real. They make it worth returning to, week after week.

What separates a forgettable supporting character from one audiences genuinely love? Let's look at how the best shows do it — with examples from some of our favourite cancelled series.

Give Them Their Own Arc

The best supporting characters aren't just there to serve the protagonist's story. They have their own desires, conflicts, and growth. In Scorpion, Toby Curtis and Happy Quinn's slow-burn romance was as compelling as any mission. In The OA, BBA (Phyllis Smith) had one of the most moving arcs in the series — a lonely teacher who finds purpose and courage through a story she barely understands.

Let Them Be Competent

A supporting character who exists only to make the protagonist look good is boring. The best supporting characters are good at what they do. In Startup, Izzy Morales is a technological genius who drives the plot as much as Nick or Ronald. In Archive 81, Mark is the loyal friend who keeps the real-world investigation going while Dan is trapped in the past. When supporting characters have skills and agency, the whole show is stronger.

Let Them Surprise You

The most memorable supporting characters defy expectations. In Teenage Bounty Hunters, Bowser Jenkins could have been a grizzled bounty hunter cliche — but Kadeem Hardison plays him with warmth, humour, and genuine fatherly affection for the twins. He's the heart of the show. In Startup, Wes Chandler (Ron Perlman) should be a simple villain. Instead, he's a man with his own code, his own vulnerabilities, and a daughter he genuinely loves.

Give Them Relationships Outside the Protagonist

Supporting characters feel real when they have connections to each other, not just to the lead. In Scorpion, the relationships between Toby, Happy, and Sylvester were as important as their dynamic with Walter. In The OA, the five new "homer" group members — Steve, French, Jesse, Buck, and BBA — formed their own bonds separate from OA herself, making their collective loss at the end of Part II even more devastating.

Let Them Have Flaws

Perfect supporting characters are boring. The best ones have real, visible flaws that affect the story. In Startup, Ronald's ambition repeatedly puts everyone at risk. In Scorpion, Sylvester's anxiety disorders are a genuine obstacle that the team must work around. Flaws make characters feel human — and humans are what audiences connect with.

The Greatest Supporting Characters

Looking across all our shows, a few stand out as masterclasses in supporting character writing: BBA (The OA), Bowser Jenkins (Teenage Bounty Hunters), Toby and Happy (Scorpion), Wes Chandler (Startup), and Cabe Gallo (Scorpion). Each one could carry their own show. The fact that they exist to make another character's story better is a gift to the audience.

Great supporting characters are one reason we love TV. And when a show is cancelled, losing those characters — their arcs unfinished, their futures unknown — is part of the pain. Browse our fan-written endings and see how the supporting characters we love get the closure they deserve.