He played college football at Northern Illinois, and was selected by the San Francisco 49ers in the first round of the 2014 NFL draft.

In 2013, he led the Huskies in tackles (95), interceptions (7) and pass deflections (12), while earning national recognition as a third-team All-American by the Associated Press.

Coming out of Northern Illinois, Ward was projected to be a first or second round pick by the majority of NFL draft experts and scouts.

On March 7, 2014, he opted to participate at Northern Illinois' pro day even though he was still injured and performed all of the combine drills except for the bench press.

[10] He was the third safety selected behind Calvin Pryor (18th overall, New York Jets) and HaHa Clinton-Dix (21st overall, Green Bay Packers).

[12] Ward competed with Antoine Bethea and Craig Dahl throughout training camp for the starting strong safety position.

Ward returned to the 49ers and was again named the backup free safety to Eric Reid under new head coach Jim Tomsula.

[14] On January 3, 2016, he collected a season-high ten combined tackles and defended a pass in a 19–16 overtime win over the St. Louis Rams.

Ward finished his second season with career-high 57 combined tackles (48 solo), six pass deflections, a sack, an interception, and a touchdown in 16 games and eight started.

[17] Ward started the season-opener against the Los Angeles Rams and collected three solo tackles and two pass deflections during a 28–0 shutout victory.

[18] During Week 10, Ward made seven solo tackles and a season-high four pass deflections, as the 49ers lost to the Cardinals on the road by a score of 23–20.

[21] Ward finished his third season with a total of 53 combined tackles (43 solo), a career-high 12 pass deflections, a sack, and an interception in 11 games and 10 starts.

[23] Head coach Kyle Shanahan named Ward the starting free safety to begin the regular season.

Ward suffered a hamstring injury and was unable to play in the season-opener against the Carolina Panthers and was replaced by Jaquiski Tartt.

[24] On September 17, 2017, Ward made his season debut and recorded five combined tackles and deflected a pass in a 12–9 road loss to the Seahawks.

The following week, he made his first start as a free safety and collected a season-high seven solo tackles during a narrow 41–39 loss to the Rams.

[30] In Super Bowl LIV against the Kansas City Chiefs, Ward recorded a team high 11 tackles during the 31–20 loss.

[32] In Week 12 against the Rams, Ward forced fumbles on Jared Goff and Malcolm Brown that were both recovered by the 49ers during the 23–20 win.

[43] Later in the season, after missing a further 3 games due to a hamstring injury, Ward returned for Week 13 against the Broncos where he recorded an interception with 20 seconds remaining to secure a 22–17 victory.