This yellow bird fed yesterday in our garden in Northwest Missouri. I have not been successful in identifying it. It has markings very similar to the male Yellow Grosbeak; however, that bird is from Mexico and Arizona. It has a beak that is black.
Another choice would be a Baltimore Oriole. The Baltimore Oriole Female is a small oriole with olive-brown upperparts, yellow-orange wash on the head and breast, and gray to white underparts. Wings are dark with two white bars. Adult male is mostly bright orange with black hood and back, black wings with orange shoulder patches and white-edged feathers, and black T-shape on tail. First year male is similar to female but has black throat patch. Immature resembles female. The Baltimore Oriole is not nearly a vibrant yellow as this bird.
The Prothonotary Warbler is indigenous to our area. It is a medium-sized warbler with olive-green back and gray wings and tail. Head, neck, and underparts are vibrant yellow; undertail coverts are white. Female and juvenile are duller and have olive-green wash on heads and faces. This could be the female because of its head markings. However, the beak on the warbler is black.
Although I am uncertain my choice would be the Yellow Warbler. The Yellow Warbler is a small warbler with bright olive-yellow upperparts and brilliant yellow underparts with rust-brown streaks on breast and sides. Wings are dark with two white bars. Tail is dark with yellow-tinged edges. Female has fewer streaks on breast. It doesn't seem to have the coloring on the head. It's beak is black, as well.