'asap' originates from English, specifically the phrase 'as soon as possible', where the words 'as...as' and 'soon' combine to express immediacy; 'asap' is an abbreviation/initialism formed from the initial letters of that phrase.

'asap' developed in the 20th century (especially in business, military, and telegram contexts) as a written abbreviation of the older phrase 'as soon as possible', which itself uses words ('as', 'soon', 'possible') that date back to Old and Middle English (e.g. Old English 'sona' for 'soon').

Initially used mainly in written, terse communications (telegrams, memos, orders) to request quick action, it has become widely used in both spoken and written informal and semi-formal contexts to mean 'do this quickly'.