PopCo (2004) is a novel by British author Scarlett Thomas. It tells a story of twenty-nine-year-old Alice Butler, a quirky, fiercely intelligent loner with an affinity for secret codes and mathematics. She works for the huge toy company named PopCo, where she creates snooping kids' kits - KidSpy, KidTec and KidCracker. At the company conference Alice and her colleagues are brought into developing the ultimate product for the teenage girls.

The novel has been compared to Cryptonomicon by Neal Stephenson, with similarities including a buried treasure subplot and flashbacks to Bletchley Park.

PopCo was a 2004 book of the year in Time Out and The Independent on Sunday