The 41-year-old actor dedicated an Instagram post to his co-star on Wood's 37th birthday Sunday.
Bloom shared a throwback photo of himself and Wood enjoying a funny moment together. The pair played the elf Legolas and the hobbit Frodo Baggins in the Lord of the Rings trilogy of films.
"HBD brotha #ElijahWood we still so young tho," Bloom captioned the snapshot, adding a tears of laughter emoji.
Bloom and Wood reunited with Viggo Mortensen, Dominic Monaghan and Billy Boyd, who portrayed Aragorn, Merry and Pippin, in January 2017. Wood had reflected on his time on the Lord of the Rings set in an interview the month prior.
"I remember being there two months out from shooting and just being surrounded by this positive energy of 'We're a part of something really special," the actor told The Huffington Post.
"It was the most extraordinary experience of my life," he added. "It's a wild thing to look back on."
The Lord of the Rings movies are based on the J.R.R. Tolkien book series of the same name. Ian McKellen, who played Gandalf in the films, said in December that he'd be open to reprising the wizard in a new, Amazon series adaptation.