According to the Pew Research Center (2017) the overwhelming majority of Western Europeans support same-sex marriage, even though these positions conflict with those of the Roman Catholic Church and some other Christian churches.

Support for same-sex marriage is highest in Sweden (88%), Denmark (86%) and the Netherlands (86%), and lowest in Finland (64%), Portugal (59%), and Italy (59%). Interestingly, Sweden also has very positive views of the church and religious intuitions: most Swedes believe the church and religious intuitions help the poor and needy (81%), strengthen and bring communities together (82%), although far fewer believe they protect and strengthen morality in society (46%).

Italy is where the highest percentage of respondents oppose legal gay marriage (38%). Italy and Switzerland are the only countries surveyed where same-sex marriage has not been legalized, although both countries allow civil unions. Christians are less likely than those who are religiously unaffiliated to support or favour gays and lesbians to marry legally. However, even among Christians, large majorities across Western Europe favour legal gay marriage. According to Christians surveyed: 41% of highly committed Christians, 74% of moderately committed Christians, and 84% of lesser (low) committed Christians favour allowing gays and lesbians to marry legally. An average of 66% of Western European Christians surveyed favour gays and lesbians being able to marry legally. Favour stands at 87% with those who are religiously unaffiliated.

Western Europeans are more likely to support same-sex marriages than Americans. Approval in the US stands at 61% as of 2019 while the average across Western Europe is 75%.