Saddlebags are bags that are attached to saddles.
In horse riding, saddlebags sit in various positions, on the back, side, or front of the saddle. Most attach to the saddle by straps and ties. They can be made from various materials. Although leather was the traditional material, it is heavier and requires more maintenance than many modern versions. There are several types: Pommel bags (which sit in front of the saddle), traditional paired saddlebags (which lie on the hips of the horse, on either side of the cantle), and assorted smaller bags such as a cantle bag (a small tube-like bag that sits just behind the saddle), or a single small saddle bag that may be carried on the off-side (right hand side) of an English saddle.
Pannier-style bags are sometimes fitted over a pack saddle used for packing gear on a horse or other pack animal (often, a mule or donkey) rather than for carrying a rider. In Turkish Anatolia, Iran and Baluchistan, saddlebags are traditionally woven in wool, with a front face decorated with Soumak and a plainer flatwoven back. Slits are left along the opening for a rope to close and secure the bag to the pack animal.
In bicycling, a saddlebag or seat bag is a bag attached under the saddle or seat. Smaller bags are typically used to hold a few items such as spare inner tubes, puncture repair kit, tools, rain gear, food, first-aid kit, etc. Seat bags are common on touring bicycles, racing bicycles, and cross country mountain bikes.
Bags range from tiny to large (over 25 liters). Smaller bags, known as seat bags, wedge packs, or seat packs fit completely under the saddle. Larger bags which project behind and sideways are usually called saddlebags; a well-known example is the Carradice Long Flap, for many years a staple of British cycle tourists especially on the weekends.