Yokoyama (横山) is a Japanese surname. Notable people with the surname include:
Akihito Yokoyama (b. 1961), Japanese golfer
Chisa Yokoyama (b. 1969), Japanese voice actress and singer
Go Yokoyama in fact Tsuyoshi Yokoyama (b. 1983), Japanese kickboxer
Hideo Yokoyama (b. 1957), Japanese novelist
Hirotoshi Yokoyama (b. 1975), Japanese football player
Hokuto Yokoyama (b. 1963), Japanese politician (Democratic Party of Japan)
Isamu Yokoyama (1889-1952), general in the Imperial Japanese Army
Juri Yokoyama (b. 1955), Japanese volleyball player
Katsuya Yokoyama (1934–2010), renowned player and teacher of the shakuhachi, a traditional Japanese vertical bamboo flute
Ken Yokoyama (横山健) is the founder of the punk record label, Pizza of Death Records.
Ken Yokoyama (横山剣) is a member of Crazy Ken Band.
Kenzo Yokoyama (b. 1943), Japanese football player and coach
Knock Yokoyama (1932–2007), Japanese comedian and politician
Kumi Yokoyama (b. 1993), Japanese football striker
Marumitsu Yokoyama in fact Okitaka Yokoyama (1780–1854), Japanese late Edo period samurai and founder of the Tōkyūjutsu
Masafumi Yokoyama (b. 1956), Japanese football player
Masami Yokoyama (b. 1981), Japanese volleyball player
Matsuo Yokoyama (b. 1927), president of Walt Disney Enterprises of Japan
Matsusaburō Yokoyama (1838–1884), pioneering Japanese photographer, artist, lithographer and teacher
Minehiro Yokoyama (b. 1971), Japanese ski mountaineer
Mitsuteru Yokoyama (1934–2004), Japanese manga artist
Naoki Yokoyama (b. 1949), Japanese electrical engineer
Sakujirō Yokoyama (1864–1912), early disciple of Kanō Jigorō
Satoshi Yokoyama (b. 1980), Japanese football player
Seiji Yokoyama (b. 1935), Japanese incidental music composer
Shizuo Yokoyama (1890–1961), Japanese general in the Imperial Japanese Army
Shōmatsu Yokoyama (1913–1992), Japanese physician
Sumiko Yokoyama (b. 1974), Japanese cross-country skier
Taikan Yokoyama, pseudonym of Sakai Hidemaro (1868–1958), major figure in pre-WW2 Japanese painting
Takayuki Yokoyama (b. 1972), Japanese football player
Takashi Yokoyama (1913–194?), Japanese swimmer
Takuya Yokoyama (b. 1985), Japanese football player
Tomonobu Yokoyama (b. 1985), Japanese footballer
You Yokoyama (b. 1981),Japanese idol, singer, actor, radio host and lyricist
Yui Yokoyama (b. 1992), Japanese idol, member of girl-group AKB48
Yuji Yokoyama (b. 1969), Japanese football player