Sweden outlawed sex not based on mutual consent, with campaigners hoping other European countries would also toughen up rape legislation after the #MeToo anti-harassment campaign.
With the new law, Sweden will join a small number of countries, including Britain and Canada, where the lack of consent in sex, even without violence, is enough to constitute a crime.
Details about the law on the Swedish government website said there will no longer be a requirement to prove violence or the threat of violence to obtain a conviction.
The law, due to come into force on July 1, stopped short of making expressed consent a condition for consensual sex but stressed passivity was not a sign of agreeing to sex.
Women's rights campaigners said they hoped the law would spark change across Europe where most nations still define rape as an act carried out with the use or threat of violence.
"While there is still a great distance to travel, we are hopeful that today's decision will herald a Europe-wide shift in legislation and in attitudes," Anna Blus, a researcher on women's rights for Amnesty International, said in a statement.
Law and order is likely to be a major issue in Sweden's parliamentary election in September with the populist, opposition Sweden Democrats linking public concern about a rising crime rate to an increase in immigrants.
The government said the incidence of sexual offences was rising in Sweden with young women facing the greatest risk but too few of these offences were reported.
The new law will introduce two new offences, negligent rape and negligent sexual abuse, carrying a maximum prison term of four years.
The new law, as published previously, stated that "in the judgment of whether participation is voluntary, it should be taken into special consideration whether consent has been expressed in words or action".
"If a person wants to engage in sexual activities with someone who remains inactive or gives ambiguous signals, he or she will therefore have to find out if the other person is willing," the law read.
Elin Sundin, head of Swedish consent campaign group Fatta, said the move came as women globally were stressing the importance of "bodily rights" in the wake of #MeToo.
"When it comes to sexual consent and integrity and bodily rights it is something close to the heart of many women," Sundin told the Thomson Reuters Foundation.
