Antonio Ardón Soto was born in Alajuela, Alajuela Province, Costa Rica on 2 September 1888. His parents were Rodolfo Ardón Jiménez (1859–1917) and Angelina Soto Jinesta (1866–1896). He had at least four siblings.

In 1912, he married Elisa Ardon Moya, his first cousin. This marriage would last for nearly 67 years before his wife’s death in 1979, at the age of 94. The couple had five children: Maria Isabel (1912–1913), Maria Isabel (1914–2008), Antonia Angelina (1919-2019), José Antonio (1921–2010) and Victor Manuel (1923–1996). For his career, he worked as a government employee during the presidencies of León Cortés and Otilio Ulate, with his responsibilities including the management of the Barra del Colorado Wildlife Refuge in the Tortuguero Conservation Area. In addition to his government job, he also worked as a salesman and travel agent.

In 1987, at the age of 99, an article was written about him for La República. At the time, he was still able to read the newspaper without glasses. Aside from a hip injury forcing him to walk with the aid of two canes, he was said to be in perfect health, and had rarely been sick. When asked about any plans he had for the future, he expressed his goal of living to the age of 125.

In September 1998, he celebrated his 110th birthday, becoming the first known person in Costa Rican history to become a supercentenarian. While he reportedly maintained his memories and cognitive faculties as of his 109th birthday in 1997, he began suffering from dementia by the time he had turned 110, and could no longer walk.

One of his second cousins, Claudia Soto Saborio (1909–2020), would also later become the oldest living person in Costa Rica, reaching the age of 111. They were related by a shared set of great-grandparents: Bernardo Soto Herrera (1791–1856) and María Josefa Quesada González (1794–1878).

Ardon Soto died of decubitus ulcer septicemia in Rio Segundo, Alajuela Province, Costa Rica on 3 November 1998 at the age of 110.