Final answer:
The 2008 "Best Animated Feature" Oscar winner with minimal early dialogue is the Pixar film WALL-E. Dialogue begins when the character EVE is introduced, about 20 minutes in.
Step-by-step explanation:
The movie that won the 2008 "Best Animated Feature" Oscar which did not have any dialogue until the title character's love interest appeared about 20 minutes into the film is WALL-E. Created by Pixar Animation Studios and distributed by Walt Disney Pictures, WALL-E is particularly noted for its minimal dialogue in its early sequences.
The movie begins with showing the desolate, waste-covered Earth and follows the lonely robot, WALL-E, who is tasked with cleaning up the planet. It's only when EVE, the sleek reconnaissance robot and WALL-E's love interest, arrives that we hear consistent dialogue, and the robots' 'voices' become a central part of the film.