Lajos Kassai (born 16 September 1960) is a Hungarian bowyer, archer and equestrian. He is primarily known for his work reviving the traditional art of mounted archery, including adapting it into a modern sport. For his work he received the Officer's Cross of the Order of Merit of the Republic of Hungary.

Lajos Kassai started making his bows in the mid-1980s and was competing successfully in field archery. Then based on the work of Karoly Cs. Sebestyen and Dr Gyula Fabian, using modern materials and technologies, he reconstructed and as first one in the world started series production of the traditional Hungarian bow used in the age of the Hungarian Conquest. Eventually bow-making became his primary profession, and he became the first in the world to mass-produce this style of bow. Besides Hungarian, Kassai makes other types of traditional bows, including; Scythian, Hun (asymmetric type), Avar, and Mongol.

We are not to follow our ancestors, we are to follow what they were following.

— Lajos Kassai,

Kassai created the competitive rule system of horse archery in the late 1980s, and started to propagate this new sport, first in Hungary, and from the 1990s in the rest of Europe, the United States and Canada. He made himself familiar with kyūdō in Kamakura, Japan, and travelled to Shaolin in China to study.

He summarized his experiences in his book Lovasíjászat ('Horse Archery'), which since its issue has been translated into German, English and Russian.

He founded the center of Hungarian horse archery, Kassai-völgy, near Kaposmérő. Horse archery centers based on the Kassai school are currently operating in fourteen countries, and organize world cups regularly.

In 2011, the University of Physical Education accepted the education practice developed by Kassai and began horse archery training. Hungary is the first country in the world where one can get a teaching diploma in horse archery.