The Million Second Quiz is an American game show that was hosted by Ryan Seacrest and broadcast by NBC. The series aired from September 9 to September 19, 2013. For one million seconds (11 days, 13 hours, 46 minutes, and 40 seconds), contestants attempted to maintain control of a "money chair" by winning trivia matches against other contestants, earning money for every second they occupied the chair. At any given moment, the four highest-scoring contestants other than the one in the chair were sequestered together. When time ran out, the four top scorers received the money they had accumulated and competed in a stepladder playoff for a top prize of $2,000,000.

Executive produced by Stephen Lambert, Eli Holzman, and David Hurwitz, The Million Second Quiz was positioned as a live, multi-platform television event, which Lambert dubbed "the Olympics of quiz", that would help to promote NBC's lineup for the 2013–14 television season. The series was cross-promoted through several NBCUniversal properties, and NBC broadcast a live prime time show for each night of the competition (except for September 15, due to Sunday Night Football) and a two-hour finale. Using a mobile app, viewers could play the game against others and potentially earn a chance to appear as a contestant during the prime time episodes. Outside the prime time episodes, the program was also webcast throughout the competition by means of the Million Second Quiz app and NBC.com.

Critics argued that the confusing format of The Million Second Quiz, along with its lack of drama and technical issues with the show's app during the first days of the series, caused viewers to lose interest in watching it on air. Despite peaking at 6.52 million viewers for its premiere, ratings steadily dropped during the show's run before rising again near the finale.