| Dr | Luiz | Oliveira | CEPETRO/Unicamp | Brazil | Sustainable Development | Best Researcher Award | |
| Prof | PLE | olivier | Université Savoie Mont Blanc | France | Materials Science and Engineering | Excellence in Innovation | |
| Dr | Olakunle | Olorntobi | Universiti Malaysia Terengganu | Malaysia | Climate Change Mitigation and Adaptation | Excellence in Research | |
| Dr | Olakunle | Oloruntobi | Universiti Malaysia Terengganu | Malaysia | Climate Change Mitigation and Adaptation | Excellence in Research | |
| Dr | Oluseye | Olugboyega | Obafemi Awolowo University | Nigeria | Construction Management | Best Researcher Award | |
| Assist. Prof. Dr | Adewale | Olutumise | Adekunle Ajasin University | Nigeria | Climate Change Mitigation and Adaptation | Best Researcher Award | View Profile |
| Dr | Ahmed | Omar | Cairo University | Canada | Structural Engineering | Top Researcher Award | |
| Mr | Rustem | Omarov | National Research Moscow State University of Civil Engineering | Russia | Materials Science and Engineering | | |
| Mr | Ali | Omidkar | University of Calgary | Canada | Environmental Engineering | Best Researcher Award | View Profile |
| Mr | Isreal | Onifade | HRI | United States | Environmental Microbiology | Excellence in Research | View Profile |
| Dr | NYAMBANE | ONTITA | Central south university, china | Kenya | Environmental Microbiology | Excellence in Innovation Award | View Profile |
| Prof. Dr | Christian | Opp | faculty of Geography, Universität Marburg | Germany | Environmental Hydrology | Best Researcher Award | View Profile |
| Dr | Innocent | Osuizugbo | Bells University of Technology, Ota | Nigeria | Construction Management | Best Researcher Award | View Profile |
| Dr | Qiang | Ou | Chongqing University | China | Geotechnical Engineering | Best Researcher Award | View Profile |
| Prof | Hamid | Ouadi | Mohammed V University of Rabat | Morocco | Green Infrastructure | Clean Energy Integration in Civil Engineering Award | View Profile |
| Mr | Zakaria | OUAOUJA | ONIRIS VetAgroBio | France | Sustainable Development | Best Researcher Award | View Profile |
| Dr | Mohamed | Ouf | Concordia University | Canada | Green Infrastructure | Research Excellence Award | View Profile |
| Dr | SAID | OUKAHOU | Sultan Moulay Slimane University | Morocco | Materials Science and Engineering | Best Researcher Award | |
| Dr | Kabir | Oyedotun | University of South Africa | South Africa | Materials Science and Engineering | Best Researcher Award | View Profile |
| Dr | Abiodun | Oyetunji | Global Banking School | United Kingdom | Sustainable Development | Best Researcher Award | |