Our qualitative interviews with 16 early-career South African researchers investigated how they view public engagement and its role in their research careers, as well as the motivations, challenges and institutional factors that shape their engagement efforts. We situate our findings in the context of high societal diversity and inequality in South Africa. We found that young researchers see public engagement predominantly as a tool to educate the public, with limited awareness of dialogic and participative approaches. While the researchers saw benefit in participating in public engagement, they disagreed on whether public engagement is an integral part of a scientist's professional role. Personal enjoyment was a key motivator for engagement, but they also wanted to make a difference in their communities by helping to address knowledge gaps. Time constraints, competing work demands and a perceived lack of skills were barriers, as well as a shortage of institutional support and engagement opportunities. The young researchers were eager to have access to engagement training and felt that public engagement deserves more recognition in their work environments. Based on this, we proposed recommendations for institutions that may help to create a supportive environment for early-career scientists who wish to participate in public engagement.