Yes — nectarine flesh is safe and vitamin-rich (it's just a smooth-skinned peach), but the pit contains cyanogenic compounds and must be removed.
Keeper's notePit it, then share. The fuzz-free skin means even birds that dislike peach skin usually accept nectarine.
What to watch out for with nectarines
Nectarines are genetically peaches without the fuzz, and they follow the same rules: soft, safe, vitamin-A-rich flesh around a pit whose kernel contains amygdalin. The smooth skin is safe and well liked once washed.