According to one embodiment, a semiconductor light emitting device includes: a stacked structural body, a first electrode; and a second electrode. The stacked structural body includes a first semiconductor layer of n-type, a second semiconductor layer of p-type, and a light emitting portion provided therebetween. The first electrode includes a first contact electrode portion. The second electrode includes a second contact electrode portion and a p-side pad electrode. A sheet resistance of the second contact electrode portion is lower than a sheet resistance of the first semiconductor layer. The p-side pad electrode is provided farther inward than a circumscribed rectangle of the first contact electrode portion, and the first contact electrode portion is provided farther outward than a circumscribed rectangle of the p-side pad electrode.