Family support through the sharing of information helps to shape and regulate the health and behaviours of family members, but little is known about how families are sharing COVID-19-related information, or about its associations with family communication quality and well-being. We examined the associations of COVID-19 information sharing methods with sociodemographic characteristics, the perceived benefits of information communication and technology (ICT) methods, and family communication quality and well-being in Hong Kong. Of 4852 respondents (53.2% female, 41.1% aged over 55 years), the most common sharing method was instant messaging (82.3%), followed by face-to-face communication (65.7%), phone (25.5%) and social media (15.8%). Female sex (adjusted prevalence ratio (aPR) 1.09), older age (aPRs 1.14–1.22) and higher household income (aPR 1.06) (all p ≤ 0.04) were associated with instant messaging use, while post-secondary education was associated with face-to-face (aPR 1.10), video call (aPR 1.79), and email (aPR 2.76) communications (all p ≤ 0.03). Each ICT sharing method used was associated with a higher likelihood of both reported benefits (aPRs 1.26 and 1.52), better family communication quality and family well-being (adjusted βs 0.43 and 0.30) (all p ≤ 0.001). We have first shown that COVID-19 information sharing in families using both traditional methods and ICTs, and using more types of methods, was associated with perceived benefits and better family communication quality and well-being amidst the pandemic. Sociodemographic differences in COVID-19 information sharing using ICTs were observed. Digital training may help enhance social connections and promote family well-being.