Figures from the Office for National Statistics show 70 new businesses were created in Gwynedd in the final quarter of last year, down from 95 over the same period the year before.
A record low number of companies were launched across the UK in the same period.
Meanwhile, 95 businesses closed in Gwynedd between October and December – up from 85 across the same period the previous year.
A government spokesperson said: "We’re backing British business through our Plan for Change, which includes tackling the scourge of late payments and introducing a fairer business rates system which incentivises investment.
"We will be publishing our plan to help small businesses start up and grow later this year."