| Proto | Proto |
| Proto-indo-européens | Proto-Indo-Europeans |
| Proto-roumain | Proto-Romanian language |
| Proto-sémitique | Proto-Semitic language |
| Protoamas | Protocluster |
| Protobionte | Protobiont |
| Protoceratopsidae | Protoceratopsid |
| protocole | protocol |
| Protocole AAA | AAA protocol |
| Protocole de Carthagène sur la prévention des risques biotechnologiques | Cartagena Protocol on Biosafety |
| Protocole de Kyoto | Kyoto Protocol |
| Protocole de Kyōto | Kyoto Protocol |
| Protocole de Madrid | Protocol on Environmental Protection to the Antarctic Treaty |
| Protocole de Montréal | Montreal Protocol |
| Protocole DICT | DICT |
| Protocole Internet | Internet Protocol |
| Protocole MESI | MESI protocol |
| Protocole MOESI | MOESI protocol |
| Protocole réseau | Protocol |
| Protocole thérapeutique | Treatment schedule |
| Protocoles des Sages de Sion | The Protocols of the Elders of Zion |
| Protoetoile | Protostars |
| Protogalaxie | Protogalaxy |
| Protomé | Protome |
| proton | proton |
| Protonation | Protonation |
| Protonthérapie | Proton therapy |
| Protoplanete | Protoplanets |
| protoplasma | protoplasm |
| protoplasme | protoplasm |
| protoplasme des germes | germ plasm |
| Protopterus | Protopterus |
| Protopunk | Protopunk |
| Protoscience | Protoscience |
| Protoss | Protoss |
| Protostomia | Protostome |
| Protostomien | Protostome |
| Prototaxites | Prototaxites |
| Protothérien | Prototheria |
| prototype | archetype |
| Prototéthys | Proto-Tethys Ocean |
| Protoxerus | African giant squirrel |
| protoxyde | monoxide |
| protoxyde d'azote | nitrous oxide |
| protozoaire | protozoan |
| Protuberance calme | Quiescent prominence |
| Protuberance eruptive | Active prominences |
| protubérance | bulge |
| protubérance solaire | solar prominence |
| protubérant | protuberant |
| Protura | Protura |
| protège-tibia | shin pad |
| protège-tympan | earplug |
| protège-épaule | shoulder pad |
| protèle | aardwolf |
| Protéasome | Proteasome |
| Protée | Proteus |
| protéger | cover |
| protéger au moyen d'une couverture | put a jacket on |
