Lee received the BFI Fellowship honor at the Saturday night award ceremony, The Hollywood Reporter reported.
"It's my great honor to be here," Depp said, adding that Lee is "a great man, a very great man indeed."
Depp went on to say that "it was certainly a childhood dream come true" to work with and learn from Lee.
The two actors worked on "Sleepy Hollow," "Charlie and the Chocolate Factory," and "Dark Shadows" together.
"I love you," Depp said in closing.
Lee said it "means an enormous amount to me" that Depp showed up at the ceremony.
"Johnny, I don't know what to say. I didn't know you were going to be here. It is a very emotional moment for me as you can probably hear," Lee said.