Hammamizade İsmail Dede Efendi (9 January 1778 – 29 November 1846) was a composer of Ottoman classical music.
He was born on 9 January 1778, at Şehzadebaşı-Fatih in Istanbul, and started studying music with Mehmed Emin Efendi, at the age of eight.
He attended rituals and learned to play the ney at the Yenikapı Mevlevihanesi, a place of Mevlevi dervish gatherings.
He also developed the composite musical modes of "sultanî yegâh", "nev-eser", "saba-buselik", "hicaz-buselik" and "araban kürdî".
His piece, Ey büt-i nev edâ olmuşum müptelâ, is featured as part of the theme for the Ottoman civilisation in the expansion for the strategy game, Sid Meier's Civilization VI: Gathering Storm.