Moore spokesman Eric Harris said the Democratic congresswoman was arrested outside a McDonald's near the Milwaukee Brewers' stadium on Miller Park Way, which is a major artery through the city. Harris said about three dozen demonstrators had gathered for the rally.
He provided a statement from Moore, in which she said she was proud to support workers "as they risk arrest in pursuit of a brighter tomorrow for their families."
"We're proud of our strong labor traditions and I'm proud to stand behind our strong and resilient workers as they fight for fair wages," she added in a statement.
During the arrest, a yellow zip tie handcuff was placed on Moore's wrists in front of her body, instead of behind, because she fractured her elbow in a fall last week and her arm is in a sling, Harris said.
Dozens of protesters in cities around the country were arrested for blocking traffic during similar demonstrations. Labor organizers in about 150 cities planned the rallies as part of their push for a $15 an hour fast-food wage.
Since the protests began in late 2012, organizers have switched up their tactics every few months to bring attention to the demonstrations, which have attracted spotty crowds. Protesters have done such things as show up at a McDonald's shareholder meeting and hold overseas rallies.