A firearm sling assembly includes an anchor adapted for connection to a firearm, a strap forming a single loop and adapted for wearing around a user's neck, and a quick-release mechanism releasably attaching the anchor to the strap. The quick-release mechanism includes a first element having a key groove defined therein, a second element having a key channel defined therein, the key channel extending between a first opening adjacent the key groove and a second opening away from the key groove, a key slidably disposed in the key channel and retractably engaging the key groove through the first opening, a biasing element acting between the key and second element to bias the key into engagement with the key groove, and a release element disposed on the second element and displaceable relative thereto to disengage the key from the key groove.