| Mr | Onesme | NZASABAYEZU | Gandhi Institute of Technology and Management | India | Others | Poverty Alleviation Strategies for Sustainable Development | Best Researcher Award | environmentalscientists.org |
| Dr | Mohammad | Obeid | Shenandoah University | United States | Computer Science | Virtual Reality | Best Researcher Award | environmentalscientists.org |
| Mr | Silas | Ochieng | DT Global | Kenya | Economics, Econometrics and Finance | Socio-Economics in Fisheries & Aquaculture | Excellence in Research | environmentalscientists.org |
| Dr | Michael | Odey | University of Calabar | Nigeria | Environmental and Sustainable Materials | Environmental Toxicology | Best Researcher Award | environmentalscientists.org |
| Mr | Samuel | Ogundahunsi | Memorial University of Newfoundland | Canada | Engineering | Energy system Engineering | Best Researcher Award | environmentalscientists.org |
| Mr | John | Ogundiran | ADAI-DEM, University of Coimbra | Portugal | Environmental Science | Indoor environmental Quality | Excellence in Scientific Innovation Award | environmentalscientists.org |
| Mr | OLUFISAYO | OJO | DURBAN UNIVERSITY OF TECHNOLOGY | Nigeria | Environmental and Sustainable Materials | Sustainability and Waste Management | Best Researcher Award | environmentalscientists.org |
| Mr | Samuel | Ojo | Case Western Reserve University | United States | Engineering | Civil and Environmental Engineering | Best Researcher Award | environmentalscientists.org |
| Dr | Oluwatayo | Ojo | Cranfield University | United Kingdom | Engineering | Energy Economics and Policy | Best Researcher Award | environmentalscientists.org |
| Dr | Dismas Odhiambo | Oketch | University of Nairobi | Kenya | Health Professions | One Health | Best Research Article Award | environmentalscientists.org |
| Assoc. Prof. Dr | Rifat | Olgun | Akdeniz University | Turkey | Others | Landscape Architecure | Best Researcher Award | environmentalscientists.org |
| Dr | Afonso | Oliveira | Universidade Federal do Oeste do Pará - UFOPA | Brazil | Ecology and Conservation | Sensoriamento Remoto e Monitoramento Florestal | Young Scientist Award | environmentalscientists.org |
| Dr | Marwa | Omar | Faculty of Medicine, Zagazig University | Egypt | Immunology and Microbiology | Medical Parasitology | Best Researcher Award | environmentalscientists.org |
| Assist. Prof. Dr | Rebaz | OMER | Koya University | Iraq | Chemistry and Materials Science | Organic and Computational Chemistry | Best Faculty Award | environmentalscientists.org |
| Dr | Tosin | Omoya | Institut de mécanique et d'ingénierie (I2M) Bordeaux | France | Environmental Science | Thermal Comfort | Best Researcher Award | environmentalscientists.org |
| Dr | Nourhen | OMRI | IPREM, UPPA, France | France | Environmental and Sustainable Materials | Rare Earth Elements recovery from mining waste | Best Researcher Award | environmentalscientists.org |
| Ms | ANNE | OMWOYO | University of Nairobi | Kenya | Environmental Science | Land resources management | Best Researcher Award | environmentalscientists.org |
| Dr | Zigmunds | Orlovskis | Latvian Biomedical research and Study Centre | Latvia | Agricultural and Biological Sciences | Plant-mycorrhiza interactions | Best Researcher Award | environmentalscientists.org |
| Dr | Abdulrazak | Otaru | King Faisal University | Saudi Arabia | Engineering | Modelling and Simulation | Best Researcher Award | environmentalscientists.org |
| Dr | Jaroslav | Otta | University of Chemistry and Technology, Prague | Czech Republic | Nanotechnology | Gas sensor technologies | Best Researcher Award | environmentalscientists.org |