Sōichirō Hoshi is a Japanese voice actor and singer born on May 30, 1972, in Aizuwakamatsu, Fukushima Prefecture. He is affiliated with the talent agency Arts Vision. His interest in a voice-acting career was sparked during his second year of high school after watching the Studio Ghibli film Kiki's Delivery Service and recognizing the work of a voice actor. This led him to enroll in the voice actor and narration department at the Tokyo Announcement Academy, from which he graduated as an honorary student.

Hoshi has portrayed a wide array of characters across anime, video games, and original video animations (OVAs). One of his notable early leading roles is Kaoru Hanabishi in the romantic comedy series Ai Yori Aoshi and its sequel Ai Yori Aoshi: Enishi. He is widely recognized for his portrayal of Kira Yamato in the Mobile Suit Gundam SEED franchise, including Gundam SEED and Gundam SEED Destiny. Other significant anime roles include Son Goku in Saiyuki, Kazuki Fuuchouin in GetBackers, Keiichi Maebara in the Higurashi When They Cry series, Masaru Daimon in Digimon Data Squad, and Tomoki Sakurai in Heaven's Lost Property. In video games, his roles include Sanada Yukimura in the Sengoku Basara series, Kilik in the Soulcalibur series, and various characters in the Harukanaru Toki no Naka de franchise.

Throughout his career, Hoshi has been a frequent collaborator with other voice actors. Notably, he worked as a regular radio assistant on Megumi Hayashibara's program, Megumi Hayashibara's Heartful Station, for several years after being invited following their co-starring role in Lost Universe. He has also lent his voice to villainous characters, such as Goro Akechi in Persona 5 and Lio Shirazumi in The Garden of Sinners. In addition to acting, Hoshi has pursued a singing career; his single Shining Tears sold approximately 40,000 copies.

Hoshi's work has earned him recognition and accolades within the industry. He won the voice actor category in the Anime Grand Prix, a prestigious annual award from Animage magazine, for three consecutive years in 2002, 2005, and 2006. At the inaugural Seiyu Awards in 2007, he was nominated for Best Actor for his role as Keiichi Maebara in Higurashi no Naku Koro ni and for Best Supporting Actor for his role as Kira Yamato in Mobile Suit Gundam SEED Destiny.