Is there a Hamcrest "for each" Matcher that asserts all elements of a Collection or Iterable match a single specific Matcher?

Use the Every matcher.

import org.hamcrest.beans.HasPropertyWithValue;
import org.hamcrest.core.Every;
import org.hamcrest.core.Is;
import org.junit.Assert;

Assert.assertThat(people, (Every.everyItem(HasPropertyWithValue.hasProperty("gender", Is.is("male")))));

Hamcrest also provides Matchers#everyItem as a shortcut to that Matcher.

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Full example

@org.junit.Test
public void method() throws Exception {
    Iterable<Person> people = Arrays.asList(new Person(), new Person());
    Assert.assertThat(people, (Every.everyItem(HasPropertyWithValue.hasProperty("gender", Is.is("male")))));
}

public static class Person {
    String gender = "male";

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }
}

IMHO this is much more readable:

people.forEach(person -> Assert.assertThat(person.getGender()), Is.is("male"));