The 'Hot and Fun' singer apparently proposed to the fashion designer and model last summer, according to WENN.
© Rex Features / Henry Lamb / BEI
Williams and Lasichanh were spotted at the world premiere of The Dark Knight Rises on Monday (July 16), where Lasichanh was seen sporting a large diamond ring.
The couple have a 3-year-old son named Rocket together, and are notoriously private with their relationship.
Williams has yet to publicly comment on the engagement reports.
The 39-year-old musician recently previewed a new track produced with Usher called 'Twisted'.
Listen to 'Twisted' by Usher and Pharrell Williams below:
Photo gallery - 'The Dark Knight Rises' world premiere:
Copyright: WENN Dan Jackman
