Deborah Oluwaseyi Joshua (born December 21, 1985),professionally known by her stage name Seyi Shay, is a Nigerian based English singer-songwriter, recording artist, performer,and record producer.

Shay was born and raised in London, England, to Nigerian parents. Her mother was from Northern Nigeria and her dad is a native of Ife. She has two elder brothers and an older sister. She and her siblings were raised by their single mother. Shay grew up in a religious setting, and felt like a single child for the most part. She started visiting Nigeria when she was two years old, and eventually attended the Command High School in Maryland, Lagos.She went back to London to complete her undergraduate studies. Her interest in music was influenced by members of her household. Her late mother was a chorister, and her sister used to compose songs for TV.Moreover, her brother was a radio and club disc jockey. Shay started performing at the age of 6, and was part of her secondary school choir. She performed for the London Community Gospel Choir during their world tour, which included 13 cities in Japan. Shay was applauded for her performances in Japan. She studied music at a local UK college, and went on to study Business Management at the University of East London.

Her music career took an upswing when she signed her first ever record deal with No Apology, a record company affiliated with George Martin. In 2006, Shay formed a girl band in the UK called Boadicea; they were managed by Ron Tom, the founder and manager of All Saints and Sugababes. The band separated after two years, and Shay decided to partake in the From Above UK singing audition. After the conclusion of the audition, she emerged as the lead vocalist for the aforementioned defunct group. The group consisted of five girls, including Shay. They got signed to Mathew Knowles' management company after performing for him. They were taken to Houston to undergo energetic vocal and dance trainings. The group supported Beyoncé while she was in the UK for her I Am... World Tour.They presented an award at the 2011 MTV Europe Music Awards, and had their own MTV reality show called Breaking From Above, which aired in over 166 countries around the world.The group later disassembled, and Shay had an opportunity to continue her management deal with Matthew Knowles as well as secure a recording contract with Sony. Shay decided to joined Flytime Music after getting an offer from them. Shay has worked with a number of musicians, including Justin Timberlake, Brian Michael Cox, Darey, Bilal, Michelle Williams, Chip, Rob Knoxx, H-Money, and Cameron Wallace.

Shay was introduced to Sound Sultan during his visit to London in 2011. After listening to some of her demos, Sultan convinced her to relocate to Nigeria and pursue her musical career there.During a project with Sound Sultan in the UK, Shay was introduced to Cecil Hammond of Flytime Promotions. Hammond signed Shay to his record label (Flytime Music), and decided to launch her solo career in Nigeria.