Bella `` Bel '' Kaufman ( May 10 , 1911 -- July 25 , 2014 ) was an American teacher and author , best known for writing the 1965 bestselling novel , `` Up the Down Staircase '' .
Bella `` Bel '' Kaufman ( May 10 , 1911 - July 25 , 2014 ) was an Ukrainian-American teacher and author . She was best known for writing the 1965 bestselling novel `` Up the Down Staircase '' .