The findings showed that children who owned cell phones were significantly more likely to report being a victim of cyberbullying, especially in grades three and four.
The increased risk could be tied to increased opportunity and vulnerability.
Continuous access to social media and texting increases online interactions, provides more opportunities to engage both positively and negatively with peers, and increases the chance of an impulsive response to peers' postings and messages, the researchers said.
"Parents often cite the benefits of giving their child a cell phone, but our research suggests that giving young children these devices may have unforeseen risks as well," said Elizabeth K. Englander, Professor at Bridgewater State University in Massachusetts.
For the study, the team collected survey data on 4584 students in grades 3, 4 and 5. Across all three grades, 49.6 percent of students reported owning a cell phone. Overall, 9.5 per cent of children reported being a victim of cyberbullying.
Researchers also noted that the older the student, the more likely s/he was to own a cell phone: 59.8 percent of fifth graders, 50.6 percent of fourth graders, and 39.5 percent of third graders.
The results, to be presented at the 2017 American Academy of Pediatrics National Conference and Exhibition in Chicago on Monday, are a reminder for parents to consider the risks as well as the benefits when deciding whether to provide their elementary school-aged child with a cell phone.
"At the very least, parents can engage in discussions and education with their child about the responsibilities inherent in owning a mobile device, and the general rules for communicating in the social sphere," Englander said.