E100 or E-100 may refer to:
Electronics
- Casio Cassiopeia E-100, a pocket-size PC
- iRiver E100, a portable media player
Vehicles
Automobiles
- Baojun E100, a Chinese electric microcar
- JMEV E100, a Chinese electric city car
- Toyota Corolla (E100), a Japanese compact car lineup
Military vehicles
- Panzerkampfwagen E-100, a proposed German World War II super-heavy tank
Other uses
- Curcumin, food coloring from turmeric designated by E number E100
- Neat ethanol fuel, or E100, a fuel blend with almost 100% ethanol