Cajal:
- Nicolae Cajal (1919 - 2004), a Romanian Jewish physician, academic, politician, philanthropist
- Santiago Ramón y Cajal, a Spanish histologist, physician, pathologist
- Cajal Institute
- Cajal cells
- Cajal–Retzius cell
- Interstitial cell of Cajal (ICC)
- Cajal bodies (CBs)
- Cajal (crater), a tiny lunar impact crater