The latest figures reveal that 56.5 per cent of the 3,476 babies born across the area in 2016 have parents who were not married or in a civil partnership when the birth was registered. That's a slight increase on the previous year.
Marriage or a same-sex civil partnership is the family setting for 43.5 per cent of children.
The figures mean that parents in Wolverhampton are less likely to be get married before having children than the average UK couple. Nationwide, 52.3 per cent of babies have parents in a legally recognised relationship.
The figures on births, released by the Office for National Statistics, show that in 2016, 34 per cent of babies were registered by parents who are listed as living together but not married or in a civil partnership.
Nicola Haines from the ONS said: "Our data shows that the overwhelming majority of births are registered jointly by two parents."
The ONS said that across the country cohabiting couples with children are becoming more prevalent. When counted alongside those who are married or in a civil partnership it means that 77 per cent of babies born in Wolverhampton in 2016 have a family setting that includes two parents at home.
The birth records show that in 2016, 271 children in Wolverhampton were registered by their mother alone, with no record of the father. A further 516 babies had parents who were recorded as living at different addresses. Together these children make up 23 per cent of all the babies born in the area in 2016.
The ONS says that the figures for the whole of England and Wales show that the proportion of single parent birth registrations was at the lowest level since 1980.