Objective: Rapidly increasing numbers of confirmed cases and deaths during the 2019 coronavirus disease outbreak (COVID-19) resulted in widespread psychological problems in the Chinese population. The purpose of this study was to investigate the sleep quality and changes in sleep patterns before and during the outbreak in the general population in China and to determine factors related to sleep quality. Methods: This cross-sectional study was conducted using an online questionnaire from 20 February to 29 February 2020 in China. Socio-demographic data, self-designed COVID-19-related characteristics, sleep patterns, and Pittsburgh Sleep Quality Index (PSQI) scores were obtained. Single factor analysis and multivariate binary logistic regression analysis were used. Results: A total of 1897 individuals were included in our study, and 30.0% of participants reported suffering poor sleep quality (PSQI>8). Logistic regression analysis found that the factors related to sleep quality included poor physical health (OR = 3.382, p < 0.001), respiratory disease (OR =1.629, p = 0.008), other diseases (OR = 2.504, p = 0.012), suspected case of COVID-19 in the same community (OR = 1.928, p = 0.002), confirmed case of COVID-19 in the same community (OR = 2.183, p = 0.007), worry about being infected (OR = 2.336, p < 0.001), >1 h/day spent hearing COVID-19 information (OR = 1.960, p < 0.001), time difference in midpoint time in bed (OR =1.230, p < 0.001), and time difference in time in bed (OR = 0.711, p < 0.001). Conclusions: Our study revealed that more than one-fourth of the participants suffered poor sleep quality during the COVID-19 outbreak. In addition to the poor health status and COVID-19-related anxiety, delayed sleep phase and reduced time in bed impacted sleep quality in the general population in China.(c) 2021 Elsevier B.V. All rights reserved.