Armour-piercing discarding sabot (APDS) is a type of spin-stabilized kinetic energy projectile for anti-armour warfare. Each projectile consists of a sub-calibre round fitted with a sabot. The combination of a lighter sub-calibre projectile with a full-calibre propellant charge allows for an increase in muzzle velocity compared to full-calibre rounds, giving the round increased armour-penetration performance. To further enhance their armour-penetration capabilities, APDS rounds typically feature a hardened core made from tungsten or another hard, dense material.

For a given calibre, APDS ammunition can effectively double the armour penetration of a gun when compared to full-calibre rounds such as AP, Armour-piercing Capped (APC), and Armour piercing Capped Ballistic Cap (APCBC) projectiles.

APDS-rounds were commonly used in large calibre tank guns up until the early 1980s, but have since been superseded by armour-piercing fin-stabilized discarding sabot (APFSDS) projectiles, which use fin-stabilization and can be fired from smoothbore guns. APDS rounds remain in use for small or medium calibres, such as in saboted light armour penetrator (SLAP) ammunition.