Florentino Ariza’s uncle; his father Don Pius V Loayza’s brother. Uncle Leo XII is one of the founders of the River Company of the Caribbean and is President of the firm when Florentino is first looking for a job. Unlike Don Pius V Loayza, Uncle Leo XII has taken care of Florentino by giving Tránsito Ariza money throughout the young boy’s life and later by finding his nephew a job as a telegraph operator and in various positions in the company. Although Uncle Leo XII has a high socio-economic status, he cares less about material benefits than about emotional, artistic pursuits such as singing. He also supports Florentino’s sexual endeavors after seeing Florentino have an affair in the company office. These characteristics suggest that he is more sensitive and fanciful than his official position might suggest, thus demonstrating that there is often a gap between people’s private and public lives. After Uncle Leo XII retires, Florentino is chosen as the new President of the River Company of the Caribbean.