Are orange seeds edible

Ignoring the irresponsible, and paranoid alternative medicine zealotry of the last answer, the truth is that orange seeds contain amygdalin (often called B-17--a misnomer) which is a type of nitriloside, of which Laetrile is derivative of. Human gut flora converts these compounds to a cyanide, which is obviously highly toxic.

The widely recognized Memorial Sloan-Kettering Cancer Center in New York advises against taking Laetrile or amygdalin supplements as no evidence supports their effectiveness as a treatment of any conditions, and because of the aforementioned cyanide problem.

Conversely, the pith (white flesh under the peel, surrounding the orange) of Oranges is edible, and appears to be highly nutrient and antioxidant dense.

While you likely won't suffer too many ill effects from accidentally eating some orange seeds, it isn't advisable to be eating large quantities of them.