The actor currently appears in Fox's Bones and has helmed four episodes of the crime drama.
Boreanaz wrote on Twitter: "When does True Blood start up? I'd like to direct an epp of that (sic)."
Boreanaz previously played the vampire Angel on Buffy the Vampire Slayer and its spinoff Angel between 1997 and 2004.
He previously admitted that he still finds it "challenging" to direct episodes of Bones.
"You want to make this show as dynamic as possible," he explained. "It doesn't get any easier - which is a good thing, because you want to keep pushing the bar."
True Blood returns to HBO on June 26.
> Sam Trammell teases True Blood love interest
Watch the latest preview from the fourth season of True Blood below: