Lough O’Flynn is a 300 acre rich limestone lake located in Co Roscommon just north of Ballinlough village. There are good stocks of wild and stocked brown trout averaging about 1.5 lbs with fish to 3 to 4lbs sometimes caught. Lough O’Flynn is renowned for its prolific hatches of Mayfly and some particularly good fishing can be had from mid-May to early or sometimes mid-July on dry patterns such as Green Drake, Spent Gnat and a variety of Wulffs. The Mayfly season often runs well beyond the early part of June. Later in the season from mid-June onwards the sedge season in an important period. In August and September anglers dapping a Daddy Long Legs and grasshopper can get reliable results.

Traditional wet flies work well on O’Flynn. These include Sooty Olive, Golden Olive, Claret and Mallard, Dabblers, Watson’s Fancy, Dunkeld just to mention a few.