Luo or Lo refers to the Mandarin romanizations of the Chinese surnames 羅 (Simplified Chinese: 罗, pinyin: Luó, Jyutping: Lo4) and 駱 (Simplified Chinese: 骆, pinyin: Luò, Jyutping: Lok3).
Of the two surnames, wikt:罗 is much more common among Chinese people.
In Teochew, 罗/羅 is most commonly transliterated as Low while in the Hokkien dialect it is romanized as Loke.
In North Korea, 羅 is transcribed as 라 (Ra) and South Korea is transcribed as 나 (Na).
[1] The origin of the Luo surname dates back to descendants of Luo, a feudal state which existed during the Shang dynasty to the Warring States period (modern day Hubei).