Jaan Leetsar was born on April 3, 1946. He studied at the Estonian Academy of Agriculture and graduated in 1971 as a hydrotechnical engineer.
From 1982 to 1986, he also studied at the Institute of Economics of the Academy of Sciences of the Estonian SSR. He received his PhD in economics in 1987. In 1997, he earned a second doctoral degree. His research focused on land use and cooperative activities.
Leetsar worked as an engineer and leading specialist in the field of land reclamation and water management. From 1990 to 1992, he was the director general of the Estonian Farmers' Central Union.
From 1992 to 1994, Leetsar served as Estonia's Minister of Agriculture. He helped shape Estonia's agricultural and rural policies. From 1994 to 1995, he was a member of parliament.
Since 1994, Leetsar worked at the Estonian University of Life Sciences. He was an associate professor and later a lecturer. He taught cooperative studies, land use, and regional policy. He supervised research and participated in international projects.
Leetsar authored numerous books and articles. He received several awards, including the Estonian University of Life Sciences' award for popularizing science.
Jaan Leetsar will be remembered for his contributions to the development of Estonia's rural life and economy. He was dedicated to knowledge and society.