| Z | Zepto | - | Astronomy |
| Z | Zetta | - | Astronomy |
| ZA | South Africa (ISO 3166 Digram) - Zambia (FIPS 10-4 Country Code) - Zettaampere | - | Astronomy |
| ZA | Zeptoampere | - | Astronomy |
| ZA | Zhuang Language (ISO 639-1 Code) | - | Astronomy |
| ZAF | South Africa (ISO 3166 Trigram) | - | Astronomy |
| ZAMS | Zero Age Main Sequence | - | Astronomy |
| ZANU | PF -Zimbabwe African National Union - Patriotic Front | - | Astronomy |
| ZAR | South African Rand (ISO 4217 Currency Code) - Zaire (ISO 3166 Trigram | - | Astronomy |
| ZAS | Zylinder Abschaltung System | - | Astronomy |
| ZBT | Zero-Balance Transfer (accounting) | - | Astronomy |
| ZC | Zeptocoulomb | - | Astronomy |
| ZC | Zettacoulomb | - | Astronomy |
| ZCU | Zimbabwe Cricket Union | - | Astronomy |
| ZF | Zeptofarad | - | Astronomy |
| ZF | Zettafarad | - | Astronomy |
| ZG | Zeptogram | - | Astronomy |
| ZG | Zettagram | - | Astronomy |
| ZH | Chinese Language (ISO 639-1 Code) | - | Astronomy |
| ZH | Zeptohenry | - | Astronomy |
| ZH | Zettahenry | - | Astronomy |
| ZHA | Zhuang Language (ISO 639-2 Code) | - | Astronomy |
| ZHO | Chinese Language (ISO 639-2 Code) | - | Astronomy |
| ZI | Zebi | - | Astronomy |
| ZI | Zimbabwe (FIPS 10-4 Country Code) | - | Astronomy |
| ZIP | Zoning Improvement Plan Code | - | Astronomy |
| ZJ | Zeptojoule | - | Astronomy |
| ZJ | Zettajoule | - | Astronomy |
| ZK | Zeptokelvin | - | Astronomy |
| ZK | Zettakelvin | - | Astronomy |
| ZL | Zeptolitre | - | Astronomy |
| ZL | Zettalitre | - | Astronomy |
| ZM | Zambia (ISO 3166 Digram) | - | Astronomy |
| ZM | Zeptometre | - | Astronomy |
| ZM | Zettametre | - | Astronomy |
| ZMB | Zambia (ISO 3166 Trigram) | - | Astronomy |
| ZMK | Zambian Kwacha (ISO 4217 Currency Code) | - | Astronomy |
| ZN | Zeptonewton | - | Astronomy |
| ZN | Zettanewton | - | Astronomy |
| ZN | Zinc | - | Astronomy |
| ZOPFAN | Zone Of Peace | - | Astronomy |
| ZR | Zaire (ISO 3166 Digram; Obsolete 1997) | - | Astronomy |
| ZR | Zirconium | - | Astronomy |
| ZS | Zeptosecond | - | Astronomy |
| ZS | Zettasecond | - | Astronomy |
| ZS | Zettasiemens | - | Astronomy |
| ZT | Zeptotesla | - | Astronomy |
| ZT | Zettatesla | - | Astronomy |
| ZU | Zulu Language (ISO 639-1 Code) | - | Astronomy |
| ZUG | Z User Group | - | Astronomy |
| ZUI | Zooming User Interface (zoo-wee) | - | Astronomy |
| ZUL | Zulu Language (ISO 639-2 Code) | - | Astronomy |
| ZV | Zeptovolt | - | Astronomy |
| ZV | Zettavolt | - | Astronomy |
| ZW | Zeptowatt | - | Astronomy |
| ZW | Zettawatt - Zimbabwe (ISO 3166 Digram) | - | Astronomy |
| ZWD | Zimbabwe Dollar (ISO 4217 Currency Code) | - | Astronomy |
| ZWE | Zimbabwe (ISO 3166 Trigram) | - | Astronomy |
