Born in Pskov region. In 1905 the family moved to Polotsk. After graduating from the Vitebsk men's gymnasium and pedagogical courses he worked as a teacher in Polotsk. In 1925 he became Secretary of the Polotsk local history Association. In 1929 he graduated from the Belarusian state University, taught at the Polotsk forest College. During the war he was evacuated. In 1944, he returned to his former position, where he worked until his retirement in 1960. He was active in local history. Many times he was elected Deputy of the Polotsk city Council of workers ' deputies.
He was awarded medals and certificates of the Presidium of the Supreme Council of BSSR.
The title of Honorary citizen of Polotsk was awarded in 1967.
Trade Union Committee of Educators of the Pedagogical Faculty of the Belarusian State University. I.P. Deynis is in the top row, the fourth from the left. 1928
Ivan Petrovich Deynis with his wife Lyubov’ Georgiyevna. 1930s
Teachers of Polotsk Forestry College. 1951
Polotsk ethnographers - S. A. Klokov and I. P. Deinis. 1954
The first Polotsk Working School. Drawing by I. P. Deynis. 1978
Ivan Petrovich Deynis with children. 1967
Burial place of the Deynis family. 2010
