Is a Ginkgo tree a conifer?
The scientific answers are pretty clear: Gingkos are not closely related to the conifers, they are closer related to the cycads. See this phylogenetic tree based on the 18S RNA from paper 2:



It shows that conifers and Ginkgos are relative close related, but not on the same sub-branch of the tree. The last common ancestor between Ginkgos and Conifers is older than the one between Ginkgo and Cycadales. This classification has been made on the basis of genome comparisions and also based on an analysis of the chloroplasts.

References:


Chloroplast Phylogenomics Indicates that Ginkgo biloba Is Sister to
Cycads
Molecular Phylogeny of Ginkgo biloba: Close Relationship Between
Ginkgo biloba and Cycads
Advances in Ginkgo biloba research: Genomics and metabolomics pe
rspectives