The 181 series (181系) (and the earlier 151 and 161 series variants) was a Japanese limited express electric multiple unit (EMU) type operated by Japanese National Railways (JNR).

The 151 series trains were introduced in 1958 on Kodama limited services on the Tokaido Main Line.

[1] 161 series trains were introduced in 1959 on Toki limited services on the Joetsu Line.

[1] All 151 and 161 series cars were subsequently modified to become 181 series alongside newly built 181 series cars.

[1]