Yoo Seung-ho made his entertainment industry debut in 1999 through a cellphone commercial. The following year, he landed his first television role in the MBC series Daddy Fish. In 2002, he debuted in the big screen in the movie The Way Home, in which he won Best Young Performer in International Film in the 2003 Young Artist Awards. In 2005, he took home the Best Young Actor trophy at the KBS Drama Awards for his work in Immortal Lee Soon-shin and Precious Family. In 2006, he starred in the movie Hearty Paws, which earned him the Best Young Actor citation at the 2007 Korea Movie Star Awards. Also in 2007, he was named Best Teen Actor at the SBS Drama Awards for his appearance in the sageuk King and I. In 2009, he became part of the hit MBC sageuk Queen Seon-deok, in which he bagged the Best New Actor honors at the MBC Drama Awards. In 2010, he joined the KBS2 teen series God of Study, which scored him various acting nominations. In 2016, he led the SBS courtroom drama Remember—Son’s War, in which he received an Excellence Award at the SBS Drama Awards. In 2017, he took on the leading role in the MBC sageuk Ruler—Master of the Mask, opposite Kim So-hyun. He picked up a Top Excellence Award and was also nominated for the Daesang at the 44th MBC Drama Awards for his performance in the series.

Yoo Seung-ho began his mandatory military service on March 5, 2013 and was discharged on December 4, 2014.