Oliver Stanley Livingstone Cayasso Guerrero (September 17, 1906 – August 4, 1986) was a Nicaraguan baseball player active from the 1930s to the 1950s.

[3] In 1941, he joined the Cinco Estrellas club; technically part of the Nicaraguan National Guard, Cayasso's on-field performance saw him promoted to the rank of lieutenant.

[3] Cayasso played as an amateur for the vast majority of his career, eschewing professional baseball opportunities in Mexico and the American Negro leagues due to a desire to represent Nicaragua in international competition.

He was part of the first ever Nicaragua national baseball team that played at the 1935 Central American and Caribbean Games.

[3] After his playing career ended, Cayasso managed the Nicaragua national team at the 1965 and 1969 Amateur World Series.