Scottish Labour Party MSP Mary Fee lodged the motion, which was supported by eight of her colleagues, reports Robot 6.
The motion states: "That the Parliament welcomes the news that the Marvel comic, X-Men, will feature its first same-sex marriage, which will feature Northstar, believed to be the first openly gay comic superhero; understands that, in 1992, Marvel was the first comic publisher to reveal a gay superhero; notes that Northstar is not the first gay character to have had a same-sex marriage in the comic book world, and agrees that same-sex marriage should not be restricted to the world of literature and fantasy."
The declaration has no legislative weight but is made as an expression of support.
A similar motion recently marked Eddie Izzard's effort to run 27 marathons in 27 days as a tribute to Nelson Mandela.
Astonishing X-Men #50 saw X-Man Northstar propose to his lover Kyle.
The following issue will feature the wedding.
Right-wing religious group One Million Mums has launched a protest against the comic.