Treseissyllt Farm Campsite is a small, privately run Certificated Site (CS) operated under the Camping and Caravanning Club, located near Fishguard in Pembrokeshire, Wales.

As a CS, it can accommodate up to five caravans or motorhomes and up to ten trailer tents or tents, making it a quiet, intimate retreat rather than a large commercial campground. The site is classed as a Hideaway, reflecting its secluded character.

Facilities include flushing toilets, showers, washbasins, Wi-Fi, and a designated dog walk, and pets are welcome.