Inbound and outbound service had seen delays of up to 30 minutes while the lower level of Grand Central was closed and searched, according to Metro-North.
The suspicious package was found at about 9 a.m. on the lower level, but the area was reopened just after 10 a.m. when the investigation concluded, according to NBC New York.
The delays inconvenienced many at the start of the long Memorial Day holiday weekend.
Click here to follow Daily Voice Greenwich and receive free news updates.