Derek Jeter -- YES, I'M ENGAGED TO HANNAH DAVIS

It's the end of an era ... NY Yankees superstar Derek Jeter is officially (almost) off the market for good -- confirming he is in fact engaged to S.I. swimsuit cover model Hannah Davis.

Jeter revealed his relationship status in a blog on "The Player's Tribune" about his dog -- writing, "He was a Christmas gift last year from my fiancée, whose family had Mastiffs growing up."

See what he did there? He casually dropped the term "fiancee."

And just like that ... the greatest bachelor in the history of bachelordom is hanging it up.

Congrats.

#JessicaAlba #JessicaBiel #MariahCarey #MinkaKelly #VanessaMinnillo #VidaGuerra #JordanaBrewster #TyraBanks #ManyManyManyMore...