Casey Acosta is a main character, being the brother of Heather and having a mutual crush on Sammy.
Casey is the son of Candi and Warren Acosta, and the brother of Heather. His parents were divorced before the series started. He lived with his dad in Sisquane, but after Warren moved to Hollywood, he moved in with Heather and Candi. Casey is a long-time friend of Taylor Briggs since they were in kindergarten. Casey and Sammy kiss at the end of Sammy Keyes and the Wedding Crasher.
Casey has reddish brown hair and "chocolatey brown eyes".Plus he has fainted freckles. He wears jeans and flannel shirts. Sammy thinks he is handsome, and when she saw him at Brandon McKenze's pool party, she thought his shoulders were "surprisingly muscular". Sammy was teased about having a crush on him by her friends Holly, Marrissa, and Dot.
Even though he's Heather's brother, Casey is the exact opposite of her and has a dislike for her; thinking of her as an embarrassment. He has stuck up for Sammy, and he took a liking to her before she even knew him. He has a crush on Sammy, and they grew closer in Sammy Keyes and the Wild Things. Sammy thought that it was sweet that Casey doesn't want to cuss in front of her.
Casey has knowledge of treating blisters, when he helped Sammy's blistered feet on the backpacking trip. He also knows about hunting, like birdshots and boar poachers using bows, but he doesn't hunt. He also knows a little about drugs, but he doesn't do or sell them. He has been best friends with Taylor Briggs since they were little kids, but Casey refuses to do drugs.
Casey is a very unique person; he knows the oldies songs like "Wild Thing" and "Free Fallin' " while other kids his age haven't heard the songs or paid attention to culture. His favorite song is "Waitin' for the Rain to Fall". He likes macaroni and salsa.
He also likes to skateboard; at the end of Sammy Keyes and The Wedding Crasher, he and Sammy ride off on their skateboards holding hands.
- Heather Acosta-younger sister
- Warren Acosta- Father
- Candi Acosta- Mother
- Casey's favorite food seems to be macaroni and salsa, as he said that if he could, he would eat it every night for dinner, because he thinks it's god-like.
- In some situations, Casey has burst out into song, singing classics such as "Wild Thing"
- Before moving in with his mom and sister, Casey used to live with his dad in Sisquane, at the address of 782 Golden Oak Circle.
- Casey gives Sammy a horseshoe charm which is laced onto her shoe.