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, 羅 is much more common among Chinese people.
In Cantonese, 羅 is usually romanized as Law or Lo, and sometimes Loh, or Lowe, and 駱 is usually romanized as Lok, though the more Western-appearing romanization Locke can sometimes be found.
In Korea, 羅 is transcribed as either 라 (Ra) or 나 (Na).
In Vietnam, the name 羅 is pronounced La and 駱 is pronounced Lạc.