The word has evolved from a niche social media tag into a mainstream term for a self-portrait photograph, the editors said.
Research suggested its frequency in the English language had increased by 17,000% in the last year, they added.
Other shortlisted words included “twerk” – a raunchy dance move performed by Miley Cyrus – and “binge-watch” – meaning watching lots of TV.
“Schmeat”, meaning a form of meat synthetically produced from biological tissue, was also a contender.
The word of the year award celebrates the inventiveness of English speakers when confronted with social, political or technological change. To qualify, a word need not have been coined within the past 12 months, but it does need to have become prominent or notable in that time.
Selfie is defined by Oxford Dictionaries as “a photograph that one has taken of oneself, typically with a smartphone or webcam and uploaded to a social media website”. It was added to the Oxford Dictionaries Online in August, but is not yet in the Oxford English Dictionary, although it is being considered for future use.
Other words that were shortlisted included “showrooming” – examining a product at a shop before buying it online at a lower price – and bitcoin – a digital currency in which transactions can be performed without the need for a central bank.