The broadcaster caused a stir in August when he fronted the BBC2 current affairs programme sporting a full beard.
Speaking before last night's programme, the 63 year-old told the Radio Times: "If a chap can't shave on holiday, what can he do? Beards are so 2013."
Paxman's appearance drew a huge response when he grew the beard more than five months ago, when he branded the BBC pogonophobic - having a fear of beards.
At the time, he explained his reasons, saying: 'I have grown a beard for the last few summers, and suddenly wondered whether I really needed to shave it off to present Newsnight.
''Unless you're lucky enough to be Uncle Albert on Only Fools And Horses, Demis Roussos or Abu Hamza, the BBC is generally as pogonophobic as the late-lamented Albanian dictator, Enver Hoxha.
''I may keep it or I may shave it off, but I think I'll make my own decision.''
He later said: "For a glorious few days I have been a poster boy for a shadowy group called the Beard Liberation Front, which claims that facial hair invites discrimination.
"I'm finding it quite a heavy burden."
The Beard Liberation Front has lamented the decision to go clean-shaven, saying: "We support people's right to dress and appear as they want so, while we regret Jeremy Paxman's decision to shave off his gravitas adding beard, the choice should be entirely up to him, BBC pogonophobia notwithstanding."