Guus "Guusje" ter Horst (born 22 March 1952) is a retired Dutch politician of the Labour Party (PvdA) and psychologist.

[1] Ter Horst attended gymnasium in The Hague and subsequently studied at University of Amsterdam where she obtained a MSc degree in psychology.

In 1984 she received a PhD degree in social science on her thesis concerning the question how people who never go to the dentist can be made to do so.

In 2010 Ter Horst received one of the Dutch Big Brother Awards for her lack of nuance in the privacy debate.

Ter Horst became policy driver for the government program Doe onbeperkt mee ("Participate without limits") to empower people with disabilities in December 2022.