[1][2] On April 30, 2016, the Arizona Cardinals signed Farley to a three-year, $1.62 million contract after he went undrafted in the 2016 NFL draft.

[4][5] Throughout training camp, Farley competed for a roster spot as a backup safety and special teams contributor against Chris Clemons, Marqui Christian, Durell Eskridge, and Tyrequek Zimmerman.

[8] Upon joining the team, head coach Chuck Pagano named him the third free safety on the Colts' depth chart, behind Clayton Geathers and T. J.

[11] On January 1, 2017, Farley tied his season-high of two solo tackles in the Colts' 24–20 victory against the Jacksonville Jaguars.

[13] He became the frontrunner for the role of starting strong safety after rookie first round pick Malik Hooker sustained numerous injuries throughout OTA's and training camp.

[15] He made his first career start in the Colts' season-opener against the Los Angeles Rams and recorded ten combined tackles (eight solo) in their 46–9 loss.

[17] Farley finished the 2017 season with 98 combined tackles (60 solo), seven pass deflections, and two interceptions in 16 games and 15 starts.

He played in five games with one start before being placed on injured reserve on October 12, 2018 with shoulder, groin, and wrist injuries.

[27][28] Farley was elevated to the active roster in the first three game of the regular season, against Los Angeles Chargers, Cardinals and Titans, and reverted the next day to the practice squad.