Carlos Monzón was born on August 7, 1942, in San Javier, Argentina. He came from a family of Mocoví descent. His parents were Roque Monzón and Amalia Ledesma. Carlos grew up in poverty alongside his twelve siblings. When he was six years old, his family moved to Barranquitas Oeste, a poor neighborhood in Santa Fe, the capital of Santa Fe Province.

To help support his family, Carlos left school after completing third grade. He took on various jobs, including being a shoeshiner, a paperboy, and a milkman. Despite the struggles, he developed an interest in boxing during his childhood.

At the age of sixteen, he met Zulema Encarnación Torres, and they had a son named Carlos Alberto Monzón. Later, on May 11, 1962, he married Mercedes Beatriz García, who had the nickname 'Pelusa.' The couple was so poor that they could not afford to buy a marriage license. They had three children together: Silvia Beatriz, Abel Ricardo, and Carlos Raúl, who was adopted.

Monzón's boxing career started when he had his first amateur fight on October 2, 1959. It ended in a draw. After gaining a record of 73 wins, 6 losses, and 8 draws in amateur boxing, he turned professional. His first professional fight took place on February 6, 1963, where he won by knocking out his opponent in the second round.

In 1966, Monzón won the Argentine middleweight title, and in 1967, he claimed the South American middleweight title. He quickly became recognized in the international boxing scene, which led to significant opportunities in his career.

Carlos Monzón's life took a dark turn in 1988. While on vacation with his long-term girlfriend, Alicia Muñiz, they got into a heated argument. Monzón's violent behavior escalated. During this incident, he physically attacked Muñiz, leading to serious consequences. Witnesses reported that he strangled her until she lost consciousness. In a shocking act, he then picked her up and pushed her off the second-floor balcony of their hotel, resulting in her death. Monzón also suffered an injury from the fall when he followed her down.

Following this incident, Monzón was arrested and put on trial. On July 3, 1989, he was found guilty of homicide and received an 11-year prison sentence for killing his wife.

While serving time in Cárcel de Las Flores in Santa Fe Province, Monzón was granted a weekend furlough in January 1995. On January 8, while heading back to prison, he was involved in a car accident that led to his death. The vehicle he was in rolled over near Santa Rosa de Calchines, killing him and another passenger instantly. A family member in the vehicle sustained injuries.

Monzón's funeral attracted significant attention, with thousands attending and cheering for him, highlighting the complex legacy he left behind in Argentine society.