O is the 15th letter in the Alphablock gang.
O is voiced by Lizzie Waterworth.
He is an orange stripy block. His eyes are nearly always widened. He has no nose.
O is mostly mute, only communicating with his "o" sound, but he is very curious and loves to investigate things with his trusty magnifying glass. He can only say "o" and "ō"; but that does not stop him from seeing stuff from his magnifying glass. O is the only orange Alphablock.
- O is the only Alphablock who only says his sound, long or short, and his name, in every episode he appears in.
- He is also the only nose-less Alphablock.
- There are some episodes where Alphablocks only say their sound like O.
- Some of them have Alphablocks who don't speak or have no solo lines when they're outside of word magic.
- Some others have Alphablocks only saying their sounds as their solo line.
- Some others have Alphablocks saying their sound when they're not in a word.
- There are some episodes where O doesn't speak when he's outside of word magic (ex. Sleep.)