(This post was updated on July 24 2020)
This is an article identifying where some polling data from Hong Kong can be found. The Hong Kong University LibGuide for Politics and Public Administration maintains a list of statistical resources, including government data sources. Summarized resources can be readily found at at the dedicated section with the Hong Kong Economic Times.
Academic Sources
Centre for Communication and Public Opinion Survey at The Chinese University of Hong Kong (中文大學傳播與民意調查中心)
Website: http://www.com.cuhk.edu.hk/ccpos/
Sample of publication topics: Public Evaluation on Media Credibility, Usage of Traditional and New Media, The Identity and National Identification of Hong Kong People
Hong Kong Institute of Asia-Pacific Studies at The Chinese University of Hong Kong (中大香港亞太研究所民調)
Website: http://www.hkiaps.cuhk.edu.hk/eng/press_release.asp
Sample of publication topics: Popularity of HKSAR government and chief executive, attitudes related to COVID19
PORI (香港民意研究所)
Website: https://www.pori.hk/
Formerly the The University of Hong Kong Public Opinion Programme (香港大學民意研究計劃)
Sample of publication topics: Popularity of Chief Executive, Popularity of Secretaries of Departments, Popularity of Directors of Bureaux, People's Satisfaction with the HKSAR Government, People's Ethnic Identity
Lingnan University Public Governance Programme (嶺南大學公共管治研究部)
Website: https://www.ln.edu.hk/pgp/level2/pgp-sur-f.htm
Sample of publication topics: Hong Kong residential problems opinion, chief executive popularity, attitudes towards universal suffrage for selection of chief executive
Notable Pro-Establishment Polls
Polling organizations with pro-establishment orientation (according to: Hong Kong Democratic Party 2012 Press Release, InMedia News 2015 Article, The Stand News 2015 Article)
香港研究協會 (Hong Kong Research Association)
香港社會監察 (Hong Kong Society Monitor)
香港社區研究中心 (Association of Community of Hong Kong)