| Paleontology | Παλαιός / Palæos - The Story of Life | 225,869 |
| researchchemicals | Research Chemical Discussion | 224,147 |
| urbanplanning | Urban planning: The built environment | 220,595 |
| datasets | Datasets | 202,087 |
| HubermanLab | HubermanLab | 196,429 |
| telescopes | r/telescopes | 195,724 |
| UFOB | UFOB | Your UAP Library | 191,152 |
| deeplearning | Deep Learning | 186,385 |
| tornado | About tornadoes! | 185,930 |
| ScienceBasedParenting | Science Based Parenting | 173,867 |
| botany | Botany | 173,823 |
| biotech | Biotech - Engineering Biology to Service Us | 172,010 |
| AskSocialScience | AskSocialScience | 171,191 |
| emotionalintelligence | Emotional Intelligence | 168,779 |
| mathematics | Mathematics | 167,525 |
