QSD

QSD may refer to:


 * Q_code, "Is my keying defective?" / "Are my signals mutilated?"
 * Quality spread differential, a concept in finance
 * Quadrilateral Security Dialogue, a strategic dialogue
 * Quick Step–Davitamon, UCI cycling team (2003–04)
 * Syrian Democratic Forces (Quwwāt Sūriyā al-Dīmuqrāṭīya)