Catherine Cartan " CiCi" Bellis (born April 8, 1999) is an American former professional tennis player. In early 2018, she was the second youngest player in the top 100 of the WTA rankings. Bellis has a career-high ranking of world No. 35 by the Women's Tennis Association, which she achieved in August 2017. She is known for winning a match at the 2014 US Open as a 15 year old against a top-20 opponent, making her the youngest match-winner at the US Open since 1996.
Her biggest title came at the 2016 Hawaii Tennis Open, a WTA (Challenger) 125 event. She also won seven singles titles and two doubles titles on the ITF Circuit. Bellis had an accomplished junior season the same year she played in her first US Open, finishing the 2014 season as the ITF Junior World Champion for holding the year-end world No. 1 junior ranking. She also won the USTA National Junior Championship that year at 15 to become the youngest winner of the event since Lindsay Davenport in 1991.
Bellis began playing on the ITF Junior Circuit in late 2012 and mostly participated in low-level Grade-4 tournaments through the end of 2013. Her biggest triumph in the 2013 season was winning Les Petits As in France, a prestigious tournament for juniors between 12 and 14 years old.
In 2014, Bellis played only Grade-B1, Grade-1, and Grade-A tournaments, the three highest levels on the junior circuit. She had an impressive start to the year by reaching the final at her first five events, winning four of them. Specifically, she won the Copa del Café in Costa Rica, the USTA International Spring Championships and the Easter Bowl in the United States, and the Trofeo Bonfiglio in Italy. She followed up this success by also reaching the French Open doubles final with Markéta Vondroušová, which they lost in a match tiebreak. In contrast, Bellis struggled at the three Grand Slam singles events she entered that year, with her best result being a third round appearance at the French Open. Nonetheless, she took over the No. 1 ITF junior rank in early September on the strength of those four titles in the first half of the season.
In August 2014, Bellis won the USTA Girls' 18s National Championship, defeating Tornado Alicia Black in the final. At the age of 15 years and four months, she became the youngest winner of the event since Lindsay Davenport in 1991. With the victory, she also earned a wildcard into the main draw of the US Open. Bellis and Black were then both selected to represent the United States at the Junior Fed Cup along with Sofia Kenin. The trio won the title and Bellis went undefeated in seven matches. Later in the year, she also reached the semifinals at the Orange Bowl. Bellis finished the season as only the second American since 1982 to be No. 1 in the year-end girls' junior rankings, earning her the title of 2014 ITF World Champion.
Bellis closed out her junior career by reaching the semifinals at the 2015 French Open, her best singles result at a Grand Slam tournament and the only junior event she played that year.
A month after the US Open, Bellis won her first two professional titles in singles in back-to-back weeks, both in South Carolina at the $25k level. In 2015, Bellis was handed a wildcard into the main draw of the Miami Open, her first Premier Mandatory tournament. She avenged her US Open loss to Zarina Diyas in the second round, before losing to No. 1 eventual champion, Serena Williams. This helped Bellis crack the top 200 of the WTA rankings for the first time. She would reach a new career-high of No. 152 in the world during the summer. Towards the end of the year, Bellis attempted to qualify for the US Open but fell one match short.
In her first tournament as a pro, Bellis entered the Tournoi de Québec and reached another WTA Tour quarterfinal. She won her final three tournaments of the year, including two $50k titles in Canada at Saguenay and Toronto, which brought her into the top 100 for the first time. Bellis then extended her match win-streak to 14 with a WTA 125 title at the Hawaii Open in Honolulu. She capped off the tournament with a win over world No. 23 Zhang Shuai in the final, the second highest ranked player she ever defeated. Bellis finished the year ranked No. 75 and the only player under 18 in the top 100.
Bellis played in her first WTA Tour clay-court season and reached quarterfinals at the Rabat Grand Prix in Morocco. She made another third-round appearance at a Grand Slam tournament at the French Open and became just the third American aged 18-or-under to make it this far at the major in Paris since the turn of the century. Bellis also had a strong grass-court season with her first WTA semifinal at the Mallorca Open. This success away from the hardcourts took her to No. 40 in the WTA rankings.
For the second straight year, Bellis had a great run at the Stanford Classic where she dropped just two games against No. 14 Petra Kvitová to get to the semifinals, where she lost to compatriot CoCo Vandeweghe. She played at the Rogers Cup and recorded a second top-ten victory, this time over No. 8 Svetlana Kuznetsova. This helped her reach a career-high of No. 35 in the world in mid-August. She then finished the season on a five match losing-streak. Nonetheless, Bellis won the WTA Newcomer of the Year award for her rankings achievement and her solid performance across all surfaces.
At the 2020 Australian Open, Bellis defeated 22nd ranked Karolína Muchová in the second round, before falling to world No. 17, Elise Mertens.
Having competed her last match on the ITF Circuit in November 2020 in Charleston, she announced her retirement from professional tennis on Instagram on 19 January 2022.
| Australian Open | A | A | A | A | 1R | A | 3R | A | 0 / 2 | 2–2 | |
| French Open | A | Q1 | A | 3R | A | A | 1R | A | 0 / 2 | 2–2 | |
| Wimbledon | A | A | A | 1R | A | A | NH | A | 0 / 1 | 0–1 | |
| US Open | 2R | Q3 | 3R | 1R | A | A | 2R | A | 0 / 3 | 4–4 | |
| Win–loss | 1–1 | 0–0 | 2–1 | 2–3 | 0–1 | 0–0 | 3–3 | 0–0 | 0 / 8 | 8–9 |
| Australian Open | A | A | 1R | A | 1R | A | 0 / 2 | 0–2 |
| French Open | A | A | A | A | A | A | 0 / 0 | 0–0 |
| Wimbledon | A | QF | A | A | NH | A | 0 / 1 | 3–1 |
| US Open | 1R | 1R | A | A | A | A | 0 / 2 | 0–2 |
| Win–loss | 0–1 | 3–2 | 0–1 | 0–0 | 0–1 | 0–0 | 0 / 5 | 3–5 |
| Win | 1–0 | Hawaii Open, United States | Hard | Zhang Shuai | 6–4, 6–2 |
| {class="wikitable" style="font-size:85%;" !Legend |
| $80,000 tournaments (1–0) |
| $50,000 tournaments (2–0) |
| $25,000 tournaments (4–1) |
| Hard (7–1) |
| Clay (0–0) |
| Grass (0–0) |
| Win | 1–0 | ITF Rock Hill, United States | 25,000 | Hard | Lauren Embree | 6–4, 6–0 | |
| Win | 2–0 | ITF Florence, United States | 25,000 | Hard | Ysaline Bonaventure | 6–2, 6–1 | |
| Win | 3–0 | Rancho Santa Fe Open, United States | 25,000 | Hard | Maria Sanchez | 6–2, 6–0 | |
| Loss | 3–1 | ITF Surprise, United States | 25,000 | Hard | Jamie Loeb | 6–3, 1–6, 3–6 | |
| Win | 4–1 | ITF Sumter, United States | 25,000 | Hard | Valeria Solovyeva | 6–1, 6–3 | |
| Win | 5–1 | Challenger de Saguenay, Canada | 50,000 | Hard (i) | Bianca Andreescu | 6–4, 6–2 | |
| Win | 6–1 | Toronto Challenger, Canada | 50,000 | Hard (i) | Jesika Malečková | 6–2, 1–6, 6–3 | |
| Win | 7–1 | Tennis Classic of Macon, United States | 80,000 | Hard | Marta Kostyuk | 6–4, 6–7(4), ret. |
| {class="wikitable" style="font-size:85%;" !Legend |
| $100,000 tournaments (1–0) |
| $10,000 tournaments (1–0) |
| Hard (1–0) |
| Clay (1–0) |
| Win | 1–0 | ITF Orlando, United States | 10,000 | Clay | Alexis Nelson | Sally Peers Natalie Pluskota | 6–2, 0–6, 11–9 | |
| Win | 2–0 | Midland Tennis Classic, United States | 100,000 | Hard (i) | Ingrid Neel | Naomi Broady Shelby Rogers | 6–2, 6–4 |
| Loss | 2014 | French Open | Clay | Markéta Vondroušová | Ioana Ducu Ioana Loredana Roșca | 1–6, 7–5, 9–11 |
| 3 |
| 2017 | |||||||
| 1. | Agnieszka Radwańska | No. 6 | Dubai Championships | Hard | 3R | 6–4, 4–6, 6–2 | No. 70 |
| 2. | Svetlana Kuznetsova | No. 8 | Rogers Cup | Hard | 2R | 6–4, 7–5 | No. 36 |
| 2018 | |||||||
| 3. | Karolína Plíšková | No. 5 | Qatar Ladies Open | Hard | 3R | 7–6(7–4), 6–3 | No. 48 |
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