No one was injured in the incident.
The 335 passengers and 13 crew members stayed on the island about seven hours before a replacement aircraft took them back to Hawaii. United Airlines Flight 2105 took the passengers on to Guam on Saturday.
Clark said the airline is inspected the jetliner. The nature of the odor wasn't reported.
Midway Island -- or Atoll -- is an unincorporated territory of the United States.