Yes, in most cases, you will need an aerial to receive Freeview, especially if you want to watch terrestrial television channels. Freeview is a service that provides free-to-air digital television channels and radio stations in the United Kingdom. These channels are broadcast over the airwaves, and to receive them, you need an appropriate TV aerial to capture the signals and deliver them to your television.
The type of aerial you need will depend on various factors, such as your location, proximity to broadcasting transmitters, and the quality of the signal in your area. In areas with strong signal reception, a simple indoor or set-top aerial may be sufficient. However, if you are in a location with weak signals or significant obstacles (such as hills or buildings), you may require an external rooftop or loft-mounted aerial for better reception.
It's recommended to consult with a professional aerial installer or retailer in your area who can assess the signal strength and recommend the most suitable aerial for your specific circumstances.