Lockdown (also stylized as Lockdown: The Scream Next Door and Lockdown: Who Is Question Mark Face?) is a children's and teen drama mystery thriller streaming television series produced by Sinking Ship Entertainment and commissioned and distributed by YouTube Originals. Conceived, developed and produced in the midst of the COVID-19 pandemic in Canada and the United States, the scripted live-action series follows a group of socially distanced teenagers working together to solve a mystery in their neighborhood. Originally announced in April 2020, the initial ten-episode series premiered on the YouTube Originals for Kids & Family channel on June 26, 2020.

The series received a Webby Award for best educational or science video series, a Special Achievement Award from the Prix Jeunesse International festival for excellence in COVID-19 programming, the global festival that every two years recognizes the best in children and youth television, as well as the Content Innovation Award for Kids Programming. The series was also recognized by the MIPCOM Diversify TV Excellence Awards, while series stars Arista Arhin and Amanda Cheung were nominated by the Joey Awards for their performances. In 2021, the series was nominated for two Canadian Screen Awards for its writing.

YouTube Originals announced in October 2020 that it had ordered six new episodes of Lockdown as part of its focus on racial justice programming. The new season, titled Lockdown: Who Is Question Mark Face? premiered on the YouTube Originals for Kids & Family channel on November 19, 2020. The first season was also picked up for second-window by WildBrain for the Family Channel in Canada.