Kimberly Sue Yap Chiu (Tagalog pronunciation: [tʃʊ]; born April 19, 1990) is a Filipino actress and singer. Known for her performances in a range of genres across film and television, she rose to fame after winning the first teen edition of Pinoy Big Brother. Chiu's films have grossed over ₱1.36 billion at the box-office, making her one of the highest grossing box office stars of all time. Forbes Asia named her one of Asia Pacific's most influential Filipino personalities in 2020.

Dubbed as the "Multimedia Idol" by various media outlets, she initially began playing supporting roles in several television shows early in her career. Her breakthrough came following her pairing with Gerald Anderson and has appeared together in a number of projects, most notable being Sana Maulit Muli (2007), I've Fallen for You (2007) and Tayong Dalawa (2009). The following year, Chiu topped Yes! Magazine's list of 100 Most Beautiful Stars and ventured more dramatic and comedic roles. It was succeeded by a string of commercially successful projects such as The Healing (2012), Bride for Rent (2014), Etiquette for Mistresses (2015) and One Great Love (2018) in films, as well as Minsan Lang Kita Iibigin (2011), My Binondo Girl (2011), Ina, Kapatid, Anak (2012), Ikaw Lamang (2014), Love Thy Woman (2020), Linlang (2023) and What’s Wrong with Secretary Kim (2024) in television.

Chiu has received numerous accolades for her work in film and television, including a Seoul International Drama Award, a FAMAS Award, eight Star Awards for Television, and eleven Box Office Entertainment Awards. As a recording artist, all of her studio albums have been certified Gold or more by the Philippine Association of the Record Industry. She was picked by Disney Southeast Asia to model as Mulan in a special 2015 calendar shoot. In 2010, she was inducted into the Eastwood City Walk of Fame for her contributions to Philippine entertainment. Chiu is currently one of the main host of the noontime variety show It's Showtime and is a regular performer in the musical-variety show ASAP since 2006.

Kimberly Sue Yap Chiu was born on April 19, 1990. She is the fourth of five children to William Chiu, a Chinese Filipino businessman from Mindoro and Louella (née Yap; 1963–2013), a Philippine Tsinoy native who migrated from Dinagat Islands to Surigao del Sur, Philippines. She is fluent in Cebuano, Tagalog, and English, with her Waray, Hokkien, and Mandarin Chinese at a beginner level only.

Since her parents' separation in 1998, Kim had a dysfunctional relationship with both of her parents. She and her siblings Lakam, Twinkle, William, and John Paul were raised by their paternal grandmother and, as children, frequently moved residences in the Visayas; including in Tacloban, Cebu, Cagayan de Oro, General Santos, Mindoro and back to Cebu City until 2006. In 2013, she reconciled with her father "after five years of estrangement" while visiting his second partner and half-siblings in San Jose, Occidental Mindoro. A month later in June, her biological mother, Louella, fell into a coma. Following a week of hospitalization, Louella died on June 23, 2013, due to brain aneurysm. In a eulogy dedicated to her mother, she debunked rumors of animosity over her mother's child abandonment and expressed: "An angel guides me in my decisions in life. For me, that is finally my mom."

Chiu gained prominence when she won the top prize in the reality series Pinoy Big Brother: Teen Edition. She was dubbed as "Chinita Princess ng Cebu". For the show, Chiu left her hometown of Cebu City and moved to Manila. She, along with the rest of the housemates entered the Big Brother house on April 23, 2006. After 42 days in the Big Brother house, she was named the Teen Big Winner with 626,562 votes (41.4% of the total votes) at the Aliw Theatre inside the Cultural Center of the Philippines Complex in Pasay. She was the only housemate who was never nominated for eviction.

After winning, Chiu became part of Star Magic. She and her on-screen partner Gerald Anderson became regulars in ASAP XV and appeared together in several ABS-CBN shows Love Spell, comedy sitcom Aalog-Alog and in the film First Day High.

In 2007, Chiu starred in the primetime TV series entitled Sana Maulit Muli alongside Anderson which was released to significant acclaim. That year, she was nominated and eventually won the 38th Guillermo Mendoza Box Office Awards as Most Promising Female Star and Best New Female TV Personality (for Sana Maulit Muli) at the 21st PMPC Star Awards. Sana Maulit Muli was later released in Taiwan under the PTS network, under the title Chances.