'Troutfly' was a US tactical unrealised radio deception designed to support Major General Matthew B. Ridgway’s US 82^nd Airborne Division round Ste Mère Eglise in Normandy on D+1 after the commitment of 'Neptune' (iii) and 'Overlord' (7 June 1944).

The plan was for signals traffic to simulate the approach of a regimental combat team of Major General Manton S. Eddy’s US 9^th Division. The deception failed as the ship carrying the requisite personnel and equipment was redirected into the wrong area.