Amy is a slender girl with light brown hair which she keeps in pigtails under a pink and yellow helmet. She wears a black tank top with light blue jean shorts, and knee-socks and black shoes. Amy also wears a yellow beaded bracelet on her right arm and a watch on her left.
Amy lives a few houses down from Clarence. Her parents are getting a divorce (as revealed when she tells Clarence they she "doesn't know if she will be living with her mom or dad") and Amy believes she will have to move away. As a moving truck pulls into her driveway, Amy takes her bike and rides past Clarence, who is playing in the mud in his front yard. She asks him to go ride bikes with her; Clarence says he doesn't have one but Amy says he can just ride on the back of hers. Amy and Clarence goes on an adventure to find an "erratic", a rock that differs in shape and size from the natural rocks in the area, after finding out from her sister that there could be one in the park. Biking through the city, Clarence says "Hi" to many people and pets - Amy remarks that he "knows everyone". When they bike past Belson, he becomes alarmed that Clarence is spending time with a girl and sets off with Nathan, Percy, and Dustin to follow them.
Amy and Clarence make it to the park and stumble upon the erratic while pretending to be bears. They climb to the top just as Belson shows up, who decides he should be the one playing on the rock and starts a pinecone war to get them off. The war continues until Amy's watch goes off alerting her that it's dinnertime. Amy thanks Clarence for a fun day out and returns home.
She likes reading fantasy novels, which she shares with an uninterested Clarence.
Amy has a bright personality, much like Clarence. She is tomboyish and full of adventure. Amy is also very competitive and a nature-lover.
- "Pretty Great Day with a Girl" (Only major role)
- "Rough Riders Elementary" (Cameo, only In Clarence's fantasy)
- "Clarence for President (In the past)
Despite of her appearing only one episode (not including her cameo in "Rough Riders Elementary" or the flashback in "Clarence for President"), she was considered as the most favourite female character by most of the Clarence fan base, describing about she had a bit in common with Clarence as a friend to her.
The gallery for Amy Gillis can be found here.
- She has an unnamed sister, who is presumed to be older than she is.
- Spencer Rothbell confirmed on his Twitter that Amy probably isn't going to return in any future episodes and that she was moving away in "A Pretty Great Day With a Girl". Despite this, she did make cameos in future episodes.
- Her Parents are briefly seen.