Look up ab initio in Wiktionary, the free dictionary.
Ab initio is a Latin term used in English, meaning from the beginning.
Ab initio may also refer to:
- Ab Initio (company), an ETL Tool Software Company in the field of Data Warehousing.
- Ab initio quantum chemistry methods
- Marriages annulled under the Catholic Church are considered as annulled ab initio, meaning that the marriage was invalid from the beginning