Ikumi Hasegawa is a Japanese voice actress born on May 31, 1995, in Tochigi Prefecture, Japan. She is affiliated with the agency Raccoon Dog. Her interest in voice acting began in her first year of middle school after reading the manga The Prince of Tennis, and she later became fascinated with Gintama. To pursue her dream, she enrolled in a two-year vocational school while simultaneously training at Pro-Fit's voice actor training school.

Hasegawa made her debut as a voice actress in 2016 with a minor role as a female student in the anime series Orange. For several years, she continued to build her experience by voicing various supporting and minor characters in series such as Aikatsu Stars!, Citrus, and Chio's School Road. In April 2018, she was promoted from a trainee to an associate at Pro-Fit, and she became fully affiliated with the agency in April 2021. Following the closure of Pro-Fit at the end of March 2022, she moved to the newly established agency Raccoon Dog on April 1, 2022, alongside many of her former colleagues.

Her breakthrough role came in 2021 when she was cast as her first lead character, Vladilena Milizé, the determined handler in the science fiction battle anime 86. This performance showcased her ability to convey emotional depth and versatility. The same year, she also took on the role of Arcueid Brunestud in the remake of the visual novel Tsukihime -A piece of blue glass moon-, a significant casting that provided a major boost to her career at a time when she had considered leaving the industry.

Hasegawa has since become known for her dynamic and versatile voice, portraying a wide range of characters. Some of her most notable and popular roles include the energetic guitarist and vocalist Ikuyo Kita in Bocchi the Rock!; the villain-turned-heroine Desumi Magahara (also known as the Queen of Death) in Love After World Domination; the confident and popular Minami Nanami in Bottom-Tier Character Tomozaki; the principled Rishe Irmgard Wertsner in 7th Time Loop: The Villainess Enjoys a Carefree Life; and the enigmatic mage Übel in Frieren: Beyond Journey's End. Her filmography also includes roles such as Koito in My Master Has No Tail, Shino in Miss Shachiku and the Little Baby Ghost, Shion in In the Heart of Kunoichi Tsubaki, Akatsuki Minami in My Stepmom's Daughter Is My Ex, Shirai in Blue Period, Mihono Bourbon in Uma Musume Pretty Derby, Aisha Udgard in How a Realist Hero Rebuilt the Kingdom, Sorane Matsuyama in If My Favorite Pop Idol Made it to the Budokan, I Would Die, and many others. A role as "Stable keeper" in Kyō, Watashi no Monogatari ga Hashirimasu was not identified in the search results.

Beyond anime, Hasegawa is also active in video games. In addition to her role as Arcueid Brunestud in the Tsukihime series, she voices Asuna Ichinose in Blue Archive and has roles in major franchises like Fire Emblem Engage, Goddess of Victory: Nikke, and Granblue Fantasy. For some of her work in adult games, she uses the alias Ahab Katoko.

Music is a significant and celebrated part of her career. Her role as Ikuyo Kita in Bocchi the Rock! involves her being the lead singer and guitarist for the in-universe band, Kessoku Band. The band's music has been extremely successful, with their album topping charts in Japan. For her musical performance as part of Kessoku Band, alongside her co-stars Yoshino Aoyama, Saku Mizuno, and Sayumi Suzushiro, she won the Singing Award at the 18th Annual Seiyu Awards in 2024. She has also been part of other music-related projects, such as the fictional idol group ChamJam for the anime If My Favorite Pop Idol Made It to the Budokan, I Would Die.

Throughout her career, Hasegawa has participated in various radio programs. She co-hosted "Hasegawa Ikumi & Saeki Iori's GO FIGHT WIN♪" from 2020 to 2021 and later started co-hosting "I don't want to do anything with Ikumi Hasegawa and Natsumi Kawaida" in 2021.

In her personal life, Hasegawa has listed her hobbies as going to karaoke alone and taking long baths. Her special skills include singing and performing a Y-balance stretch. She holds a pre-2nd grade qualification in the Japanese Kanji Aptitude Test. She has cited voice actors Miyu Irino and Miyuki Sawashiro as people she admires.