F/O 

F/O usually stands for Fictional Other, which is a term often used by Self-shippers, mainly on Tumblr.

You can have romantic, familial and platonic F/Os!

Self Shipper 1#: Yo, I got a new F/O!!
Self-Shipper 2#: That's so cool, who are they?
Self Shipper 1#: It's Peter Parker from The Amazing Spider-Man, 2012!

F/O by enotits October 14, 2018

f/o 

Fuck off

Will you f/o mate!

f/o by Mr fuck off November 11, 2013

f/o 

Stands for "fictional other" in replacement of the term "significant other." Almost exclusively used by Kinstagram users who have a delusional belief that a fictional character is in love with them.

DNI if you post about loving my f/o 🥺🥺🥺

f/o by kinstagramspy September 9, 2021

f/o 

Fictional Other,

used by crazy delusional introjects who actually can't separate reality and fiction

"errrrm ryuuto suzuki is my #1 f/o DONT EVER INTERACT if you like him"
" oh..! "

f/o by edgemaster04 December 20, 2023

f/o 

fiction other, meaning a fictional character you self-ship/yume yourself with! it can be platonic (including found family) or romantic!

its like S/O which means significant other, but instead of significant its just,, fictional.. coz they aint real.

anyway your f/o loves you

person 1: someone just drew art of my f/o!
person 2: awhh thats so adorable!
person 3: eww why do you yume
person 1 & 2: *murders person 3 demurely*

f/o by himerabbit May 7, 2025

f/o

stands for "fictional other". used by yumeshippers to refer to the character they ship themself with.

my favourite danganronpa character is aoi asahina, and she's also my f/o

f/o by aoiasahinafangirl244 October 17, 2025

F.O 

A short version of "Fuck off"

If you're lazy and don't feel like saying the full sentence, a simple "F.O." will suffice.

hey Jason.... "F.O."

F.O by Chippity Chops November 13, 2004