[1] Rivero was born and raised in the city of Ponce, located in the southern coast of Puerto Rico, He was graduated from Central High School in San Juan.

On June 20, 1927, he received an appointment from the Honorable Felix Cordova Davila, Puerto Rico's Resident Commissioner, to attend the United States Naval Academy.

[2] During World War II, he served aboard the USS San Juan (CL-54) as a gunnery officer and was involved in providing artillery cover for Marines landing on Guadalcanal, Marshall Islands, Iwo Jima, and Okinawa.

In July 1953, the Noble participated in Operation Big Switch, moving Communist North Korean prisoners from Koje Do to Inchon pursuant to the armistice agreement.

[1] While serving as the Vice Chief of Naval Operations, Admiral Rivero spoke out in favor of the survivors of the 1967 USS Liberty incident.

He said his “most prominent memory of the Liberty” was “My anger and frustration at our not punishing the attackers.”[8] From 1968 until his retirement from the Navy in 1972, Admiral Rivero was the North Atlantic Treaty Organization's commander in chief of the Allied Forces in Southern Europe.

He was responsible of the land, sea and air forces of five nations deployed in the Mediterranean area: Italy, Greece, Turkey, Britain and the United States.

[11] Rivero died on September 24, 2000, and was buried with full military honors in the Fort Rosecrans National Cemetery of San Diego, California.

[9] On November 11, 2008, the government of Puerto Rico unveiled in the Capitol Rotunda the oil portrait of Admiral Horacio Rivero Jr.