Tomlinson, 24, looked very low-key in black jeans and an Adidas sweatshirt, while Campbell, 20, was dolled up in a short leather skirt, white crop top and grey sweater-coat, reported E! Online.
Onlookers said the pair was looking cute and couple-y at both of these dessert dates.
"He was behind her and had his arms around her. It was really sweet!" said an eyewitness of the twosome's Chicago outing. "They seemed cuddly-he was holding her for a little while."
This is not the first time the duo were seen enjoying each other's company. Earlier this month Tomlinson was "all over" Campbell at Hollywood hot spot Millions of Milkshakes, and they caught up again at an ice cream parlor in Chicago called Oberweis.