I've seen 'Voices of the Distant Stars' which was about 25 min...
And then I've seen FLCL which is six epsiodes... I haven't bought this one though, because they show it on the cartoon network so much I never felt the need to.
excluding one-shots, the shortest I've seen would be the Read or Die OVA: 3 OVA episodes, all on one disc.
"Before I formed you in the womb I knew you, and before you were born I consecrated you. I appointed you to be a prophet of all nations." --Jeremiah 1:5 Hit me up on social media! https://www.facebook.com/profile.php?id=100007205508246<--Facebook
I'm also on Amino as Radical Edward, and on Reddit as Rocklobster as well.
The shortest series I've ever seen, I think that would be Someday's Dreamers? Only 12 episodes.
Though youths grow weary and tired And vigorous young men stumble badly, Yet those who wait for the LORD Will gain new strength; They will mount up with wings like eagles, They will run and not get tired, They will walk and not become weary. -Isaiah 40:30-32