I love the name [name]Sebastian[/name] but I need nn options! I don’t like [name]Seb[/name] or Bass or [name]Bastian[/name]. I don’t mind it if its a bit of a stretch. I was thinking [name]Bas[/name], like the bas part of basil… but not crazy about that either. Ideas??!
[name]Sebastian[/name] really doesnt have any good nns to be honest with you. If you love the name then I say use it. [name]Sebastian[/name] is a handsome and stunning name that doesnt need to be ruined by any nn imo. If you are worried about your son not having a nn, I say dont fret. [name]Nick[/name] names will come that will likely have nothing to do with your son fn but will have personal meaning to you.
I agree with leah_9. If you want a nickname maybe his middle name has a nickname and he can go by his middle name nn.
I also agree with leah_9 that you shouldn’t worry about a nickname. I love the name myself and don’t have any nicknames I like either. If the name seems a bit long to you, in the middle spot either use a shorter name or one that lends easily to a nickname.
[name]Sebastian[/name] doesn’t offer many good nicknames, aside from [name]Bastien[/name] (I pronounce it [name]Bas[/name]-T-en).
[name]Ashton[/name] or [name]Ian[/name] would be nice but I feel like they take away from the feel of [name]Sebastian[/name]. Your fall back will probably be [name]Seb[/name], honestly. Everyone gets called by the first few letters of their name.
Since I also pronounce [name]Basil[/name] as Bah-zil/Bahs-il, I think [name]Bas[/name] is cute. ‘Bayz’ isn’t too much of a stretch.
Tian (T-un)
Sebas
Sebby
Or, just wait until something comes to you. [name]Buddy[/name] or [name]Bubba[/name] might stick, or a happy baby might lead to [name]Sunny[/name].
The only [name]Sebastian[/name] I’ve ever met was this scrawny smelly kid I had to work with. Everyone would call him Sebas, as in Sea Bass.
I’ve always liked [name]Ash[/name] as a nickname. I think it’s adorable and very handsome.
I’ve heard [name]Baz[/name] as a nickname for [name]Sebastian[/name]. I think it’s probably the best nickname out there. However, I think [name]Sebastian[/name] is best in full! A name doesn’t have to have a nickname, especially if you love it!
I’ve met a Sebby, but all others seem to go by the full [name]Sebastian[/name].
What about the middle name? if it has a good first initial, you could get a nick name that way… [name]Sebastian[/name] [name]James[/name] could be nn’d SJ
Hmmm. That is a hard one. I guess you could use [name]Stian[/name] and pronounce it like [name]Stein[/name] or Stayne. [name]Seb[/name] would be the automatic shortening I suspect though.
- Anon.
As of late, I have been hearing of Sebastians being called Sea Bass as a nickname. Not for babies, but by the teen years.
I have a [name]Sebastian[/name]… we call him Sebby. I was confused on nicknames before I had him too, but Sebby just rolls off the tongue 
My 4 year old [name_m]Sebastian[/name_m] goes by a nickname a lot of the time. It started out “Sebashto” when he was a newborn, then Bashto, then Bash. Then he started to call himself Sashin, which we borrowed and then shortened to [name_m]Sash[/name_m]. I wouldn’t be surprised if he is called [name_u]Ash[/name_u] someday, though a lot of people still call him Bash and Bashto. A few people do call him [name_m]Bastian[/name_m].
I was a little nervous to name him such a mouthful but I love his name and it suits my little independent, stubborn, unique kid. His full name is [name_m]Sebastian[/name_m] [name_m]John[/name_m] [name_m]Aloysius[/name_m].
Nothing I particularly like for a nn for [name_m]Sebastian[/name_m] but in an anime called [name_m]Black[/name_m] [name_m]Butler[/name_m], one of the character’s is called [name_m]Sebastian[/name_m] and the guy who has a crush on him and red calls him Bassy or Bassy-chan. Childish, I know, but it was his nn for [name_m]Sebastian[/name_m].
I know that this is too late, but I [name_u]LOVE[/name_u] the name [name_m]Sebastian[/name_m] and I adore Bash as a nickname