Rutricha Phapakithi (; born 23 September 1999), formerly Apichaya Saejung (), nicknamed Ciize (), is a Thai actress and singer. She is a former member of the girl group Sizzy under Riser Music. She gained recognition for her performances in various television series, including YOUniverse (2018), 23.5 (2024), Pluto (2024), and ' (2024).
Rutricha was born in Bangkok, Thailand as Apichaya Saejung. In July 2023, she announced on Twitter that she was changing her legal name to Rutricha Phapakithi as someone has the exact same birth name as her.
She is of Thai Chinese descent. Her Chinese name is Zeng Xishi ().
Rutricha graduated from Satriwitthaya 2 School and went on to Bangkok University where she graduated with a bachelor's degree in business Chinese in 2022.
In 2015, Rutricha made her acting debut with the television series Wonder Teacher where she played a supporting role of Cherry. She later went on to play various roles in several television series, including as May in ' (2016) and Mochi in My Dear Loser: Edge of 17 (2017).
In 2018, she landed her first main role as Nik, in the web series YOUniverse alongside Wachirawit Ruangwiwat. In the same year, she played as Ching in 'Cause You're My Boy.
In 2019, she portrayed Onnie, Smile's (Sananthachat Thanapatpisal) bestfriend in Boy For Rent. She also played as New Year, a high school student who dies from a hate gift in A Gift For Whom You Hate.
In the meantime, she signed under GMMTV and debuted as an idol under Sizzy (formerly known as Sissy) in November 2019, before they officially disbanded in October 2024.
In 2020, she portrayed Lyla in Who Are You and Pang in Tonhon Chonlatee.
In 2021, she played as Thong Hansa, the daughter of the village chief who's a rival to Lookpat (Wannarot Sonthichai) in The Prince Who Turns into a Frog. In the same year, she got the main role of Nan, a social media addict who often feels inferior to Papang (Sarunchana Apisamaimongkol) in the mystery teen miniseries The Comments. She also played as Cin, Wisa's (Phatchatorn Thanawat) personal assistant in 46 Days. She later appeared in several television series.
In 2024, she appeared in Beauty Newbie. Then she received recognition after portraying Alpha, a student council president who excels in academic, also an older sister of Ongsa (Pansa Vosbein) in the Thai girls' love television series 23.5. In the same year, she played as Fai in We Are and as Rak in Peaceful Property.
She also gained wider recognition for portraying Pang, Ai-oon's (Tipnaree Weerawatnodom) friend who involves in a messy love triangle with Pim (Ploynira Hiruntaveesin) and Jan (Preeyaphat Lawsuwansiri) in the 2024 girls' love television series Pluto. She later played as Baifern, Po's (Supha Sangaworawong) friend who's fangirling over MARS (LYKN) in '. In the meantime, she appeared in various music videos.
In 2025, she went viral for her speaking skills in three languages (Thai, English, Chinese) when she serves as the event host in Chuang Busking Day, an event where showcasing the trainees of '. In the same year, she played as Jin in Boys in Love.