He graduated with a Candidate's degree in sociology at the University of Oslo in 1992, with the thesis Lidende ledere og kompetente kalkulatører.

Næringslivsfolks symbolske kamper, which in English translates as Suffering leaders and competent calculators.

Together with Bård Tufte Johansen, he has been author of, and participated in, several successful Norwegian Broadcasting Corporation comedy TV series, such as Lille Lørdag (1995), Åpen Post (1998–2002), Uti vår hage (2003), Team Antonsen (2004), Tre brødre som ikke er brødre (2005), Uti vår hage 2 (2008), and Storbynatt, as well as the radio comedy shows Herreavdelingen (1997) and Tazte priv (2004–2005).

He has also performed stand-up comedy and theatresports and had supporting roles in Norwegian films, including Detector (2000) and United (2003).

Harald Eia is awarded the Fritt Ord Foundation Tribute for, through the programme Brainwash, having precipitated one of the most heated debates on research in recent times.Since 2017, Eia has, together with Nils Brenna, produced the podcast- and radio-series "Sånn er du", where a famous Norwegian takes a Big 5-personality test for each episode.