Saadi studied law at the Hebrew University of Jerusalem, where he was chair of the Arab Student Union.

He worked as a lawyer, dealing with security prisoners and members of the Palestinian Legislative Council who were expelled from East Jerusalem.

He became secretary general of the Ta'al party after it was established in 1996 by his brother-in-law, Ahmad Tibi.

[2] He resigned from the Knesset on 20 September 2017, and was replaced by Ibrahim Hijazi, as part of a rotation agreement between the parties within the Joint List.

[3] Ta'al ran in an alliance with Hadash for the April 2019 Knesset elections, with Sa'adi in fourth place.