The landscape of education has experienced significant changes as a result of the global COVID-19 pandemic. Central to the recent developments is the increasing concerns related to the levels of student satisfaction and performance in Mathematics within the context of online learning. This study seeks to fill the gaps in existing research literature on how mathematics is taught online during the pandemic. In particular, the goal of this research was to investigate the relationship between students' perceived satisfaction and reported academic performance in a Mathematics online class and suggest important satisfaction factors to improve student online learning experiences. The study was a descriptive research design utilizing mixed methods, and the data were collected from a volunteer sample of n = 153 respondents, composed of senior high school students from three private schools, through an adapted online survey instrument. Results showed that the association between satisfaction and performance was significant and positively correlated. Furthermore, there was a low but positive significant correlation between satisfaction with their performance. Regardless of their performance levels, students were generally satisfied with online learning. Students, however, pointed out three (3) additional factors that affect their satisfaction -- flexible and considerate task management, effective communication and subject mastery in teaching; and accessibility and clarity of educational resources. To improve online learning, these additional factors are essential to have a high level of satisfaction and performance in online learning.