According to the Hong Kong Immigration Department, visitors from over 170 countries can enjoy visa-free entry for periods varying from seven days to six months! 

Visit the Hong Kong Immigration Department website and check if you need a visa:
http://www.immd.gov.hk/eng/services/visas/visit-transit/visit-visa-entry-permit.html

In the case that a visa is required, visitors can submit their applications directly to the Hong Kong Immigration Department or through a Chinese diplomatic or consular mission in their area of residence.
 
For enquiries, please contact:
 
Hong Kong Immigration Department 
Immigration Tower, 7 Gloucester Road 
Wanchai, Hong Kong
Tel: (852) 2824 6111 
Fax: (852) 2824 1133 / 2877 7711 
E-mail: [email protected] 
Website: http://www.immd.gov.hk