| Dr | OLIVE | YEMELE MEKONTCHOU | Hohai University | China | Engineering | Water pollution research | Women Researcher Award | environmentalscientists.org |
| Mr | OLUFISAYO | OJO | DURBAN UNIVERSITY OF TECHNOLOGY | Nigeria | Environmental and Sustainable Materials | Sustainability and Waste Management | Best Researcher Award | environmentalscientists.org |
| Dr | Oluwakamisi | Akinmoladun | University of Johannesburg | South Africa | Agricultural and Biological Sciences | Animal Science, Food Safety, Food Security | Best Researcher Award | environmentalscientists.org |
| Dr | Oluwaseun | Adeniji | University of Johannesburg | South Africa | Biotechnology | Nanotechnology | Best Researcher Award | environmentalscientists.org |
| Dr | Oluwatayo | Ojo | Cranfield University | United Kingdom | Engineering | Energy Economics and Policy | Best Researcher Award | environmentalscientists.org |
| Dr | Oluwatoyin Joseph | Gbadeyan | Durban University of Technology, South Africa | South Africa | Environmental and Sustainable Materials | Waste valorization and Bioeconomic | Best Researcher Award | environmentalscientists.org |
| Dr | Omar | Sims | Cleveland Clinic | United States | Medicine and Health Sciences | Hepatology | Best Researcher Award | environmentalscientists.org |
| Mr | Onesme | NZASABAYEZU | Gandhi Institute of Technology and Management | India | Others | Poverty Alleviation Strategies for Sustainable Development | Best Researcher Award | environmentalscientists.org |
| Mr | Osama Bin | Shafaat | Aalto University | Finland | Astronomy and Astrophysics | Remote Sensing | Best Researcher Award | environmentalscientists.org |
| Dr | Oscar Alfredo | Jaramillo Salgado | Universidad Nacional Autónoma de México | Mexico | Engineering | Renewable Energy | Excellence in Scientific Innovation Award | environmentalscientists.org |
| Dr | Osvaldo | Valarini Junior | Universidade Tecnológica Federal do Parana | Brazil | Chemical Engineering | Tratamento de Água e Efluentes | Best Researcher Award | environmentalscientists.org |
| Prof | Otari | Didmanidze | Departments of Tractors and Automobiles, Institute of Mechanical and Power Engineering Named After V.P. Goryachkin, Russian State Agrarian University—Moscow Timiryazev Agricultural Academy | Russia | Ecology and Conservation | Thermophysical processes of spontaneous combustion and forced ignition of solid disperse materials | Best Researcher Award | environmentalscientists.org |
| Ms | Otgonpurev | Nergui | Nuclear Research Center, National university of Mongolia | Mongolia | Engineering | research of environmental issue, comparison of policy, engineering, physics | Best Researcher Award | environmentalscientists.org |
| Mr | Ousmane | Wane | Polytechnic University of Madrid | Spain | Agricultural and Biological Sciences | AGRO-ENVIRONMENTAL | Best Researcher Award | environmentalscientists.org |
| Prof. Dr | Özlem | Güzel | Akdeniz University | Turkey | Social Sciences | tourism psychology | Best Researcher Award | environmentalscientists.org |
| Assoc. Prof. Dr | Pablo | Ruisoto | Public University of Navarre | Spain | Psychology | Basic Psychology | Excellence in Research Award | environmentalscientists.org |
| Mr | Palinda | Perera | Earthlanka Youth Network | Sri Lanka | Environmental Science | Restoration Ecology and Ecosystem Rehabilitation | Research Excellence Award | environmentalscientists.org |
| Dr | Palwasha | Gul | Henan university of technology, china | China | Others | Food Science and Engineering | Women Researcher Award | environmentalscientists.org |
| Dr | PANAGIOTA | TSIATSIOU | AHEPA University Hospital | Greece | Medicine and Health Sciences | Laboratory / Virology | Best Researcher Award | environmentalscientists.org |
| Prof. Dr | Panagiotis | Lagouvardos | National & Kapodistrian University of Athens-Dental School | Greece | Dentistry | Operative Dentistry | Research Excellence Distinction Award | environmentalscientists.org |