The Southeast Asian country's parliament last week passed legislation approving jail terms of up to a year for anybody in Indonesia caught having sex outside of wedlock.
Cohabitation by unmarried couples can also be punished with six months in prison.
Businesses have voiced worries that the sweeping overhaul of the criminal code will be detrimental to tourism in Indonesia, which received more than 16 million visitors in 2019.
But Deputy Law and Human Rights Minister Edward Omar Sharif Hiariej on Monday dismissed those concerns, saying foreigners will not be prosecuted.
"I want to emphasise for foreign tourists, please come to Indonesia because you will not be charged with this article," Hiariej told reporters.
He said extra-marital sex and cohabitation offences would only be prosecuted if a spouse, parent or child reported it, while adultery had already been illegal for years under the previous criminal code.
In the holiday hotspot of Bali, Governor Wayan Koster also tried to allay fears about the law, saying local authorities would not check the marital status of tourists.
He said in a statement that Bali would not make any "policy changes" related to the new criminal code.
"Bali is Bali as usual, which is comfortable and safe to be visited," Koster said.
"There will be no checks on marital status upon check-in at any tourism accommodation... nor inspections by public officials or community groups."
The new criminal code still needs to be approved by President Joko Widodo and will not come into force for three years.