Prayag Dutta Joshi was an Indian writer and Sambalpuri language (allegedly also known as Kosli) activist.

He was awarded with gold medal for securing the first position in All India level Ayurveda examination held in 1938.

He is popularly known as 'Kosli bhashar Janak' (Father of Kosli Language) and also as 'Kosal Gaurav'and "KOSAL RATNA".

He was also among those who for the first time in 1986, submitted a memorandum to the President of India to include Kosli under Eighth Schedule.

His small booklet Koshali Bhasar Samkhipta Parichay is considered as a sacred text by Kosli writers as well as leaders of the Kosal movement.