The main controversies surrounding Hegsethpublished at 13:25 Greenwich Mean Time 14 January
Hegseth's nomination has proved divisive - with three controversies in particular expected to come under sharp focus during today's hearing.
Allegations of sexual assault: Hegseth was investigated over an alleged sexual assault at a California hotel in October 2017, during a Republican conference. He was never arrested or charged, and denies wrongdoing. He and the unnamed accuser reached a settlement in 2023, which Hegseth's lawyer said was a case of "successful extortion".
Women in combat roles: Hegseth has previously suggested women should not serve in combat roles, arguing that "over human history, men in those positions are more capable".
Alleged heavy drinking: US media have reported that Hegseth's drinking concerned his colleagues during previous roles at a veterans' advocacy group and Fox News. Spokespeople for Hegseth have dismissed the claims, and he has also reportedly told senators that he's stopped drinking and will remain sober if confirmed.