Secret Royal Inspector & Joy is a 2021 South Korean television series starring Ok Taec-yeon and Kim Hye-yoon. It aired on tvN from November 8 to December 28, 2021. It is also available for streaming on iQIYI and Viu in selected territories.

Kim Hye-yoon is a South Korean actress and model. She first became known through her portrayal as Kang Ye-seo in JTBC's television series Sky Castle (2018–2019) and received her first leading role in television with MBC's Extraordinary You (2019) and her first leading role in film with The Girl on a Bulldozer (2022). She has been dubbed by various Korean media as the Nation's Little Sister.