The tremor struck Qingyuan at 6:48pm.
The epicentre was located in Qingcheng, a district of Qingyuan, about 180 kilometres northwest of Hong Kong.
The quake had a focal depth of about 10 kilometres.
People in nearby cities, including Guangzhou, Zhongshan, Foshan, Zhuhai and Dongguan, reported feeling the tremor.
The Guangdong Earthquake Agency said no injuries were reported and that emergency response measures were implemented.
The Hong Kong Observatory said more than 100 people reported feeling the tremor, which lasted a few seconds.
A woman, who lives in Ma Liu Shui, told RTHK what happened.
“I was at home, sitting on the floor. I felt a few minor tremors,” she said.
“I recently went to Japan where there was a stronger earthquake. It felt quite similar. But surely, this earthquake in Hong Kong didn’t feel as strong as the one in Sendai.”
A woman living in North Point said that she felt her sofa in the living room shake for about two to three seconds.