A sleeveless t shirt dress is brilliant until the air conditioning hits, or the evening turns, or you simply want to look a little more considered without changing the entire outfit. That is exactly where a sleeved version earns its place. We have been genuinely selective here because sleeves on a casual dress can go wrong quickly. Too stiff and the whole relaxed quality disappears. Too flimsy and they add nothing. What we are after is the sleeve that actually improves the dress, that gives it shape, a little structure, a reason to exist beyond covering your arms.
What you will find in this edit are t shirt dresses where the sleeve is part of why the dress works. Long sleeves that make it feel put together enough for the office. Three quarter lengths that hit a flattering point most arms appreciate. Fitted sleeves that stay out of the way and let the rest of the dress do the talking. The fabric still feels easy, the silhouette still reads casual, but there is an intention to these that the basic version lacks. Sleeves, when they are right, make the dress.