Christopher Thorndyke (クリストファー・ソーンダイク, Kurisutofā Sōndaiku?), also simply known as Chris(クリス, Kurisu?), is the main human protagonist in the anime series Sonic Xand its comic series published by Archie Comics. He is a kind and caring boy who lives in Station Square on Earth. At the start of the series, Chris finds Sonic the Hedgehog at the bottom of his swimming pool and saves him from drowning. He then hosts him, Miles "Tails" Prower, Amy Rose, Cream the Rabbit and Cheese for most of the series. Chris, very much like Tails, looks up to Sonic like an older brother figure and is always willing to do whatever he can to help his new friends.

Chris is a calm and well-mannered boy, though sometimes a bit energetic with a hunger for adventure. Despite being a "rich kid," Chris very is down-to-earth, thinking himself no different from everybody else and does not want to be treated differently despite coming from a rich family. Because of his parents' frequent absences since childhood however, Chris would often suffer from loneliness and thus longed for close companionship. Chris' friendship with Sonic and his friends would ease Chris' pain, but it would also make him worry, panic or even sink into a mind depression whenever he feared they would leave him.

Chris deeply treasures the bonds he makes with other people and will do anything to preserve them. However, this tends to give him a reckless or selfish streak, like when he fell into one of Eggman's traps in an attempt to help Sonic and his friends get home, or when he deliberately kept Sonic from returning home so he would not leave him. Regardless, Chris has a good heart and is always remorseful when his feelings get the better of him.

At the age of eighteen, Chris seemed to have gained somewhat of an attitude, especially around Helen.