The Green Bay Packers selected Hayward in the second round (62nd overall) of the 2012 NFL Draft.
He was the fifth cornerback selected in 2012 and Vanderbilt's highest defensive back drafted since Fred Vinson in 1999.

On May 11, 2012, the Green Bay Packers signed Hayward to a four-year, $3.30 million contract that includes $1.03 million guaranteed and a $847,208 signing bonus.

Hayward entered training camp competing against Jarrett Bush, Sam Shields, and Davon House for the vacant starting cornerback spot after veteran Charles Woodson was moved to strong safety to replace Nick Collins, who was released due to health concerns.
Head coach Mike McCarthy named Hayward the third cornerback on the Packers' depth chart, behind Sam Shields and Tramon Williams.

He made his professional regular season debut in the Green Bay Packers' season-opener against the San Francisco 49ers and recorded one tackle in their 30–23 loss.
On October 7, 2012, Hayward recorded two combined tackles, broke up a pass, and made his first career interception during the Packers' 30–27 loss to the Indianapolis Colts.
He intercepted a pass attempt by Andrew Luck that was originally intended for Reggie Wayne to seal the victory in the fourth quarter.
The following week, Hayward broke up three passes and intercepted two passes from Matt Schaub and T. J. Yates during the Packers' 42–24 victory at the Houston Texans.
In Week 7, Hayward earned his first career start after Sam Shields was unable to play after suffering a shin and knee injury.
Hayward went on to record three solo tackles, a pass deflection, and an interception in a 30–20 victory at the St. Louis Rams.
During the month of October 2012, he won the NFL defensive Rookie of the Month, having intercepted four passes three games.
He finished third for NFL Defensive Rookie of the Year and was named to the NFL All-Joes team.

In Week 8, Hayward recorded a season-high eight combined tackles in the Packers' 24–15 victory over the Jacksonville Jaguars.
He finished his rookie season in 2012 with 53 combined tackles (40 solo), 22 pass deflections, and six interceptions in 16 games.

The Green Bay Packers finished first in the NFC North with an 11-5 record and received a playoff berth.
On January 5, 2013, Hayward played in his first career playoff game and collected four solo tackles in the 24–10 win against the Minnesota Vikings in the NFC Wildcard game.
The Packers' were defeated 45–31 by the San Francisco 49ers the following game.
Hayward earned the highest overall grade of any slot corner ever graded by Pro Football Focus.
The Green Bay Packers selected Hayward in the second round (62nd overall) of the 2012 NFL Draft. He was the fifth cornerback selected in 2012 and Vanderbilt's highest defensive back drafted since Fred Vinson in 1999. 
On May 11, 2012, the Green Bay Packers signed Hayward to a four-year, $3.30 million contract that includes $1.03 million guaranteed and a $847,208 signing bonus.
Hayward entered training camp competing against Jarrett Bush, Sam Shields, and Davon House for the vacant starting cornerback spot after veteran Charles Woodson was moved to strong safety to replace Nick Collins, who was released due to health concerns. Head coach Mike McCarthy named Hayward the third cornerback on the Packers' depth chart, behind Sam Shields and Tramon Williams.
He made his professional regular season debut in the Green Bay Packers' season-opener against the San Francisco 49ers and recorded one tackle in their 30–23 loss. On October 7, 2012, Hayward recorded two combined tackles, broke up a pass, and made his first career interception during the Packers' 30–27 loss to the Indianapolis Colts. He intercepted a pass attempt by Andrew Luck that was originally intended for Reggie Wayne to seal the victory in the fourth quarter. The following week, Hayward broke up three passes and intercepted two passes from Matt Schaub and T. J. Yates during the Packers' 42–24 victory at the Houston Texans. In Week 7, Hayward earned his first career start after Sam Shields was unable to play after suffering a shin and knee injury. Hayward went on to record three solo tackles, a pass deflection, and an interception in a 30–20 victory at the St. Louis Rams. During the month of October 2012, he won the NFL defensive Rookie of the Month, having intercepted four passes three games. He finished third for NFL Defensive Rookie of the Year and was named to the NFL All-Joes team. 
In Week 8, Hayward recorded a season-high eight combined tackles in the Packers' 24–15 victory over the Jacksonville Jaguars. He finished his rookie season in 2012 with 53 combined tackles (40 solo), 22 pass deflections, and six interceptions in 16 games.
The Green Bay Packers finished first in the NFC North with an 11-5 record and received a playoff berth. On January 5, 2013, Hayward played in his first career playoff game and collected four solo tackles in the 24–10 win against the Minnesota Vikings in the NFC Wildcard game. The Packers' were defeated 45–31 by the San Francisco 49ers the following game. Hayward earned the highest overall grade of any slot corner ever graded by Pro Football Focus.
Casey Hayward