As with any intellectual property, the person who designs and builds the site is the one who owns it.
However, if you are paying a developer to create a site for you, once you have paid for their work, they will assign the copyright to you and the site will then belong to you.
The same principle should apply to any copywriters, photographers, videographers or other creatives that you commission.
It’s a good idea to double check your contracts to ensure that there is provision for this in place or just ask your designer if you’re not sure.
If you’d like support and advice about IP, the Business & IP Centre have lots of workshops and 1-2-1 sessions to help business owners on this topic and others.