Ward attended and played college football at Ohio State under head coach Urban Meyer. As a true freshman at Ohio State in 2015, Ward played in 12 games, recording seven tackles. As a sophomore in 2016, he played in all 13 games and had 23 tackles. Ward became a starter as a junior in 2017. Entering the 2018 NFL Draft, Ward decided not to play in the 2017 Cotton Bowl.

On December 29, 2017, Ward released an official statement through his Twitter account announcing his decision to forgo his senior season and enter the 2018 NFL Draft. Ward also decided to skip the Cotton Bowl Classic. Ward attended the NFL Scouting Combine in Indianapolis and completed the majority of combine drills, but opted to skip the short shuttle and three-cone drill. His overall performance impressed scouts and helped solidify his position as the top cornerback prospect. Ward tied for first, among all players, in the 40-yard dash (4.32s) and his broad jump (11’4″) was the best among all players, regardless of position. He also tied for second in the vertical jump (39″) among his position group and tied for eighth in the bench press (16 reps) among cornerbacks who participated.

The Cleveland Browns selected Ward in the first round (fourth overall) of the 2018 NFL Draft. Ward was the first defensive back drafted in 2018 and became the highest selected cornerback from Ohio State since Shawn Springs, who was selected third overall in the 1997 NFL Draft.

On July 24, 2018, the Cleveland Browns signed Ward to a fully guaranteed four-year, $29.16 million contract that includes a signing bonus of $19.29 million.

He made his professional regular season debut and first career start in the Cleveland Browns’ season-opener against the Pittsburgh Steelers and recorded six combined tackles, broke up three passes, and made two interceptions during their 21–21 tie. Ward made his first career interception off a pass attempt by Steelers’ quarterback Ben Roethlisberger, that was originally intended for wide receiver Antonio Brown, in the first quarter. On October 7, 2018, Ward recorded five combined tackles, tied his season-high of three pass deflections, made one interception, and a blocked field goal in a 12–9 overtime win over the Baltimore Ravens. His performance earned him AFC Special Teams Player of the Week. Overall, he finished his rookie season with 53 tackles, three interceptions, 11 pass deflections, one forced fumble, and two fumble recoveries in 13 games, of which he started 12. He was named to the Pro Bowl and the NFL All-Rookie Team.