Yes, a local partner is required before your entrepreneur visa can be approved. The partner (commonly referred as a sponsor) can be a company or individual and responsible for your repatriation if the need arises in future. If the partner is a business, a complete application form and a registration certificate will be needed.
If the partner for your application is an individual, his identity card, personal passport particulars, and an application form will be required. While these are the main requirements from the sponsor by the Hong Kong administration, you can be required to provide additional information where necessary before the visa can be approved.