The Welrod is a British bolt-action, magazine-fed pistol with an integrated silencer that was devised for covert operations during the Second World War by Major Hugh Reeves at the Inter-Services Research Bureau (later Station IX).

It is derived from "Wel" from "Welwyn" (a prefix used by covert equipment designed by Station IX) and "rod", gangland slang for gun, as a way to obscure its purpose.

[2] The Welrod was used primarily by the British Special Operations Executive (SOE) but was also used by the American Office of Strategic Services (OSS) and Resistance forces.

The exclusion of a pistol grip was apparently done to help conceal the weapon's purpose and in some groups it was called a "bicycle pump" due to its innocuous look with the magazine/grip removed.

[9] The muzzle end of the gun is ground slightly concave to minimise noise during a contact shot; this may have also improved grip against the target, decreasing the chance of missing.

The detachable single stack magazine contains six or eight rounds (depending on calibre) and serves as a pistol grip with the bottom part enclosed by the plastic cover.

[1] In 2002, Small Arms Review tested the Welrod (in .32 ACP) and found a 34-decibel noise reduction compared to a control pistol with a same length (3.25 inch) barrel for a final 122.8 decibel value.

[12] There was a plan in 1943 to drop Welrods into German-occupied territories for the mass assassination of Schutzstaffel (SS) and Gestapo officers and soldiers within a one-month period by resistance units.

[13] The Welrod was used by US Army Special Forces soldiers assigned to Detachment "A" Berlin during the Cold War[14] and by Military Assistance Command, Vietnam – Studies and Observations Group (MACV-SOG).