Qassem Lajami (; born 24 April 1996) is a Saudi Arabian professional footballer who plays as a defender for Saudi Pro League side Al-Taawoun, on loan from Al-Qadsiah and the Saudi Arabia national team.
His twin brother Ali is also a professional footballer and as of August 2023 plays as a defender for Saudi Pro League club Al Nassr.
On 1 June 2019, Lajami joined Al-Fateh on a five-year deal.
On 14 July 2024, Lajami joined Al-Qadsiah on a two-year deal.
On 3 February 2026, Lajami joined Al-Taawoun on a sex-month loan.