The case against the 24 star has been dropped, according to the New York District Attorney, who rejected the case, according to Entertainment Tonight.
"We declined to prosecute after a full investigation," the D.A. said Tuesday in a statement. "And that included speaking to the complaining witness who was quite uncooperative. Therefore, the D.A. declined to prosecute."
Sutherland and the designer he is accused of head-butting had previously announced that they had resolved their differences, clearing the way for the charges to be dropped.
Sutherland, 42, is also clear with the L.A. City Attorney's office, which investigated the actor for a possible probation violation. (He is currently serving a five-year probation term following a DUI conviction in 2007.)
The actor was charged with third-degree assault after he allegedly bashed heads with Proenza Schouler's Jack McCollough, who accidentally bumped into Brooke Shields at a Met Gala after-party May 5. Multiple outlets reported that Sutherland was intoxicated.