Šarunas Gustainis (born December 15, 1975, Kaunas, Lithuania) is a Lithuanian businessman and politician, member of Seimas (2012-2016).
In 2010 he co-founded an independent public institution - the Institute of Applied Politics (Lithuanian: Taikomosios politikos institutas), a non-profit, private, free people public institution engaged in various social, cultural, educational, etc.