Sam Worthington's showing love for the late, great producer Jon Landau ... lauding his leadership abilities -- and, referring to their hit movie "Avatar."

The actor shared a statement with Deadline early Sunday in honor of producer Jon Landau who passed away Saturday ... saying JL was a passionate producer who led with humor, strength and compassion.

And, Worthington's honoring him through what they made together too ... writing, "The People say all energy is borrowed and someday you have to give it back. I see you, Jon.” The Na’vi -- the main alien tribe from their hit movies "Avatar" and "Avatar: The Way of Water" -- are also known as "The People."

ICYMI ... Jon's family announced his passing yesterday in a statement to The Hollywood Reporter after a battle with cancer.

Landau was a Hollywood-producing legend known for hit films like "Honey, I Shrunk the Kids" and "Dick Tracy" before partnering with James Cameron for "Titanic."

The two struck up a yearslong friendship that saw them produce movies together like "Solaris," "Alita: Battle Angel" and, of course, "Avatar."

Cameron also paid tribute to Landau ... also applauding him for his humor and positive attitude -- and, saying "A part of myself has been torn away" following his death.

He's survived by his wife, Julie, his sons Jamie and Jodie and numerous extended family members. He was 63.

RIP