Luo Tianyi (Chinese: 洛天依; pinyin: Luò Tiānyī) is a Chinese Vocaloid developed formerly by Bplats, Inc. under the Yamaha Corporation, and was created in collaboration with Shanghai Henian Information Technology [zh]. She was released for the Vocaloid 3, Vocaloid 4 and Vocaloid 5 engines. Her voice is provided by the Chinese voice actress Shan Xin. Considered China's most popular virtual idol, she held a joint concert with pianist Lang Lang at the Shanghai's Mercedes-Benz Arena in March 2019.

To create strong support for the first Chinese Vocaloid, a contest was held to pick the most popular design. The winning entry would become a Vocaloid, while the runner up entries were included in the Vocaloid promotions.

The winner of the contest was named Yayin Gongyu (Chinese: 雅音宫羽; pinyin: Yǎyīn Gōngyǔ) and their entry became Tianyi's design. The first song by Luo Tianyi was "Step on Your Heart" (Chinese: 心印; pinyin: Xīn Yìn).

On April 2, 2012, Shan Xin confirmed that she had just finished her second day of recording the voicebank and mentioned that she had done an interview with Japanese reporters. According to her report, she recorded in the "Japanese way", which led to a fan asking if it would be a Japanese or Chinese voicebank. Shan Xin responded by stating to wait for the announcement. Her Japanese voicebank was not yet finished at the time of Yanhe's development. However, they mentioned that they hoped to have her released soon. Later, in November 2013, it was confirmed the vocal was cancelled.

Tianyi's Vocaloid 4 production was officially announced on March 12, 2016. Her original vocal would be improved, and it was confirmed that she would be receiving at least one additional vocal. However, the name of it was not revealed at the time, and it was unknown if she was receiving any more vocals. She was eventually released on December 30, 2017, with two voicebanks, "Meng" (Chinese: 萌; pinyin: Méng; lit. 'moe'; normal) and "Ning" (Chinese: 凝; pinyin: Níng; lit. 'solid'; power), along with two Japanese voicebanks released on May 18, 2018, "Normal" and "Sweet".

An updated Vocaloid 5 voicebank was released in February 2023, together with updated versions of Yuezheng Ling and Yanhe.

She has a pet called "Tian Dian" (simplified Chinese: 天钿; traditional Chinese: 天鈿; pinyin: Tiān Diàn), and according to her biography, is an angel sent to bring happiness via music to the world, like the Vocaloids of the past.

Luo Tianyi has also been co-opted as youth ambassador of the Chinese Communist Youth League.^{[citation needed]}