Rumi Okubo is a Japanese voice actress affiliated with the agency 81 Produce. She was born on September 27, 1989, in Ehime Prefecture, Japan, and was raised in Saitama Prefecture. From a young age, she developed a love for anime and manga, which inspired her to pursue a career in voice acting. She attended the Tokyo Announce Gakuin, and in 2009, while still a student, she won an excellence award at the Third 81 Produce Audition. That same year, she made her voice acting debut with a minor role in the television anime series Whispered Words.

Okubo's career gained momentum in 2011 when she landed her first regular role as Kaho Hiiragi in Freezing and her first leading role as Suguri Kinoshita in Happy Kappy. That year, she also began voicing two of her most enduring characters: Chinatsu Yoshikawa in the long-running comedy series YuruYuri and Ako Shirabe, also known as Cure Muse, in Suite Precure. Her performance in YuruYuri, in particular, established her as a fan favorite and led to her involvement in music units and live events with her fellow cast members.

In 2013, Okubo's rising prominence in the industry was recognized when she won the Best Rookie Actress award at the 7th Seiyu Awards, sharing the honor with Kaori Ishihara. This accolade marked her as one of the most promising new voices of her generation. Throughout the 2010s, she continued to build an extensive and diverse filmography, taking on a wide range of roles. Notable performances from this period include Nobunaga Oda in Sengoku Collection, Tsumiki Miniwa in Place to Place, Hibachi in Mushibugyō, Kazuki Ferrari in Galilei Donna, Nona in Death Parade, and the voice of the Rider-class servant Astolfo in Fate/Apocrypha.

The breadth of her work is also reflected in her consistent presence in franchise and fantasy anime. She has voiced Mia Ageha across the Pretty Rhythm and PriPara series, Cleao Everlasting in the various seasons of Sorcerous Stabber Orphen, and Soka in That Time I Got Reincarnated as a Slime and its spin-off, The Slime Diaries. Her versatility extends to more recent and high-profile series, where she has played Nana Hiiragi, the titular character in Talentless Nana, Lola in The Hidden Dungeon Only I Can Enter, Sharon Holygrail in Engage Kiss, Omoharu Nakanaka in Komi Can't Communicate, Enome in Futoku no Guild, and Nell in Reincarnated as a Sword. In 2023, she gained significant attention for her role as the internet-savvy MEMcho in the hit series Oshi no Ko. She is also set to voice Nene Himekawa in the upcoming adaptation of Tune In to the Midnight Heart.

Beyond her individual roles, Okubo is known for her warm friendships and frequent collaborations with fellow voice actors, particularly the cast of YuruYuri. Her work often extends into music, as she has been a member of numerous seiyuu idol and music units related to the series she has starred in, including Nanamori Junior High School☆Gorakubu from YuruYuri and B Komachi from Oshi no Ko. She has also been a host on radio programs such as Chaldea Radio Station Plus, related to the Fate franchise. Through her energetic performances, dedication to her craft, and wide-ranging roles from comedic to dramatic, Rumi Okubo has solidified her place as a prominent and beloved figure in the contemporary anime voice acting industry.