Since, children are affected by the coronavirus in the same way as adults, examining the children's knowledge, attitude, and practice (KAP) on COVID-19 would help in building a pandemic-resilient society. Therefore, the present study aims to investigate the knowledge, attitude, and practice regarding COVID-19 among primary school students. This online, cross-sectional study was conducted from May 18 to 20, 2021 among students aged 9 to 12 years old and having access to WhatsApp messenger on their smartphones. The study participants were selected from 17 primary schools in Kedah, Malaysia by convenience , and the Google form invitation link was shared by the schools’ guidance and counselling teachers. Analysis revealed higher females (53%) and majority aged 12 years (27.8%) out of 1207. 56% of respondents possessed good knowledge on COVID-19 (M=4.21, SD=1.16) with 73.75% overall correct responses. Children demonstrated positive attitudes (M=3.64, SD=0.67) but had a higher perceived risk of becoming infected with COVID-19 (M=3.60, SD=1.23). For practices, low scores were discovered on avoid visiting crowded places (M=2.51, SD=1.22). Knowledge has a significant effect on children’s attitudes (Beta=0.17, p<0.001) and practices (Beta=0.25, p<0.001). Comparatively, females scored lower COVID-19 knowledge than males (Beta= -0.01, p=0.65). While age was significantly associated with increased knowledge (Beta=0.13, p<0.001), whereof, year 6 students (12 years; M=4.69, SD=1.23) scored the highest. Since knowledge is a critical tool in comprehending any phenomenon, and influencing one’s attitude and practice towards it, much effort is warranted to enhance the effectiveness of government strategies and mitigate the COVID-19 outbreak.