| Prof | heekyong | oh | University of Seoul | South Korea | Environmental Engineering | Excellence in Innovation | |
| Dr | Chaewoon | Oh | National Institute of Green Technology | South Korea | Climate Change Mitigation and Adaptation | Best Researcher Award | |
| Dr | Sehyeong | Oh | Samsung Advanced Institute of Technology | South Korea | Air Pollution Control | Best Researcher Award | |
| Dr | Oluwaseun | Okimiji | Lagos State University | Nigeria | Environmental Risk Assessment | Excellence in Research | |
| Mr | Paul Michael Nii Anang | Okoe | Fugro GB North Marine Limited | United Kingdom | Others | Best Researcher Award | civilengineeringawards.com |
| Assist Prof Dr | Dilek | OKUYUCU | Erzurum Technical University | Turkey | Structural Engineering | Women Researcher Award | civilengineeringawards.com |
| 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 | civilengineeringawards.com |
| 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 | civilengineeringawards.com |
| Mr | Isreal | Onifade | HRI | United States | Environmental Microbiology | Excellence in Research | civilengineeringawards.com |
| Dr | NYAMBANE | ONTITA | Central south university, china | Kenya | Environmental Microbiology | Excellence in Innovation Award | civilengineeringawards.com |
| Prof. Dr | Christian | Opp | faculty of Geography, Universität Marburg | Germany | Environmental Hydrology | Best Researcher Award | civilengineeringawards.com |
| Dr | Innocent | Osuizugbo | Bells University of Technology, Ota | Nigeria | Construction Management | Best Researcher Award | civilengineeringawards.com |
| Dr | Qiang | Ou | Chongqing University | China | Geotechnical Engineering | Best Researcher Award | civilengineeringawards.com |