Seifeddine Jaziri was born on 12 February 1993 in Tunis, Tunisia. He came through Club Africain's youth ranks and was loaned to US Ben Guerdane before moving to Tanta SC in Egypt in 2017 — the start of an extended Egyptian career. After spells at Stade Gabésien and El Mokawloon, Zamalek SC signed Jaziri in February 2021.
His Zamalek career has been highly productive across multiple Egyptian honours: the Egyptian Premier League in 2020–21 and 2021–22, the Egyptian Cup in 2021–22 and 2024–25, the CAF Confederation Cup in 2023–24, the CAF Super Cup in 2024, and the Tunisian Kirin Cup in 2022.
The 2024 season produced 17 league matches with 4 goals plus 4 CAF Confederation Cup matches with 2 goals; 2025 has continued at the same pace with 9 Egyptian Premier League matches, 7 CAF Confederation Cup matches with 2 goals, and a goal in the Egyptian Super Cup.
For Tunisia, Jaziri has been a senior squad member for over a decade. He featured at the 2025 Africa Cup of Nations and continues to be in the senior 2026 World Cup squad picture.
A two-footed centre forward with senior leadership, hold-up play and the goal-scoring instinct that has produced consistent African club output for years, Jaziri is one of Tunisia's most experienced strikers heading into the 2026 FIFA World Cup.