Spike Spencer is an American voice actor born Charles Forrest Spencer on December 21, 1968, in Houston, Texas. He attended the University of Houston for four years, graduating from the Honors Program with a degree in Drama. His entry into voice acting came after meeting Amanda Winn-Lee on the set of a live-action film; she suggested he audition for English dubbing work at ADV Films. His early anime roles included a supporting part in Super Atragon and a leading role in Suikoden Demon Century. In August 1996, he was cast in the role that would define his career: Shinji Ikari in the ADV Films English dub of the groundbreaking series Neon Genesis Evangelion. Following ADV Films' closure, when Funimation acquired the rights to the Rebuild of Evangelion film series, Spencer was brought back to reprise his iconic role as Shinji, a character he has voiced for over two decades.

Spencer's voice work is extensive, spanning numerous anime series, films, and video games. His characters often fall into two categories: timid or emotionally vulnerable individuals and eccentric, comedic figures. Beyond Shinji Ikari, some of his most recognized anime roles include Akito Tenkawa in Martian Successor Nadesico, Dr. Gojo Shioji in Excel Saga, Hanataro Yamada in Bleach, Rolo Lamperouge in Code Geass: Lelouch of the Rebellion R2, Papillon in Buso Renkin, and Ginta in MÄR. He also voiced Majin Buu in the Bang Zoom! English dub of Dragon Ball Super. In video games, his performances include Ringabel in Bravely Default, Claude C. Kenny in Star Ocean: Second Evolution, Yeager in Tales of Vesperia, Nall in Lunar: Silver Star Harmony, and the champion Kled in League of Legends.

Spencer has demonstrated a long-standing ability to secure prominent roles across a wide variety of popular series. This includes voicing Junichirou Tanizaki in the long-running Bungo Stray Dogs franchise and its spin-off Bungo Stray Dogs Wan!, as well as Saburo Togusa in the Durarara!! series and its sequels Durarara!!×2 Shō and Ketsu. His film work includes the role of Ace Goody in both Stand By Me Doraemon and Stand By Me Doraemon 2, Yugo in Battle Angel, Snake in Black Butler: Book of the Atlantic, and Kouichi Tsuruchi in Knights of Sidonia: Love Woven in the Stars. His earlier career also includes roles such as Toshi Igarashi in both Compiler and Compiler 2, the Trade District Director in Cagaster of an Insect Cage, Dirk in Mewtwo ~Kakusei e no Prologue~, Takateru Sage in Suikoden Demon Century, and Cyborg 002/Jet Link in Cyborg 009 Vs. Devilman.

A notable achievement in Spencer's career is the recognition of his most famous character; Shinji Ikari was voted the number one greatest anime character of all time by IGN.com in 2014. His work has also extended beyond a single studio or city; he relocated from Houston to Los Angeles in 2006 to further his career. Beyond voice acting, Spencer is an accomplished public speaker, author, and coach, focusing on relationships and communication. He also holds martial arts rankings, including a brown belt in aikido and a second-degree black belt in Tae Kwon Do.