What do graduate students wear to class at ivy league universities?

Grad students all dress differently. Some are preppy types, some are hippies, some are arty types or postmodernists that wear all black, some just wear jeans, hoodies, and t-shirts.

It is important to have one good suit for important functions, but honestly, just wear whatever you are comfortable wearing.

Tan pleated slacks, a pastel colored polo shirt or dress shirt tucked in, a sweater tied around the waist or shoulders (Important: have to make sure the sweater clashes with both the shirt and pants you are wearing), and boat shoes.

I would dress nicely- avoid the sweatpants and jeans obsession! Khakis, black pants, sweaters, button ups etc always look nice

Whatever they like. There are no uniforms anymore