Lagerfeld says that his relationship with the groom stemmed back years when he attended Chanel's Little Black Jacket Exibit.
The 78-year-old had designed Barrymore and Kopelman's wedding attire, reported Us magazine.
"His father, Arie Kopelman, was the President of Chanel America. Will is divine and sweet. They're a good match!," he said.
Lagerfeld said that the white, pleated muslin and organza custom creation worn by Barrymore, 37, worked out well considering she is pregnant.
"She knew what she wanted and she got it. There was only so much we could do. But for someone who is pregnant she looked perfect," he said.
Drew and art consultant Will, 34, said 'I do' on her Montecito, California estate on Jun 2, in front of 170 guests - including her godfather Steven Spielberg, Scarlett Johansson, Reese Witherspoon and Jim Toth, Busy Philipps, and Jimmy Fallon.
