Without Lionel Messi and Neymar, whom along with Leandro Paredes and Angel Di Maria were given extra rest after their international exploits in midweek, PSG still made light work of sealing a fifth straight win.
Passed fit to feature after sustaining a calf injury while on France duty, Mbappe – the subject of three failed bids from Real Madrid at the end of August – scored his fourth goal of the season on a typically blistering counter-attack 10 minutes into the second half.
Herrera's first-half double had put PSG into a comfortable position, with promoted Clermont failing to test debutant Gianluigi Donnarumma despite plenty of attacking intent as Idrissa Gueye wrapped up an emphatic win.
Mbappe created PSG's first chance after 11 minutes, though Marquinhos was unable to direct the forward's free-kick either side of Arthur Desmas.
Clermont's resolve was punctured in the 20th minute, though, Herrera on hand to head home after Desmas had parried Achraf Hakimi's cross-shot.
Danilo Pereira would have made it 2-0 four minutes later if not for Akim Zedadka's block, yet PSG would not be denied for long.
Herrera was once again in the right place at the right time to pounce on a loose ball, this time lashing a finish into the roof of the net, while a goal-line block prevented Julian Draxler netting a third before half-time.
There was to be no such reprieve for Clermont early in the second half, Mbappe rounding the goalkeeper to finish coolly after racing onto Draxler's lofted pass.
Mbappe should have doubled his tally, or teed up Rafinha, just after the hour, only for the youngster to chip wide when one-on-one with Desmas.
He atoned moments later, a rebound from his shot falling to Gueye, who nodded in at the back post to cap off a slick display.