Kansas City Chiefs
On March 14, 2013, the Kansas City Chiefs signed Smith to a three-year, $18 million contract that includes $11 million guaranteed and a signing bonus of $6.75 million.
Smith competed for a starting job against Dunta Robinson, who was also signed as a free agent. Head coach Andy Reid named Smith a starting cornerback to begin the regular season, opposite Brandon Flowers.
In Week 6, Smith collected a season-high five solo tackles and a pass deflection during a 24–7 victory against the Oakland Raiders. On November 3, 2013, he made two combined tackles, two pass deflections, an interception, and scored his first career touchdown in the Chiefs' 23–13 win at the Buffalo Bills in Week 9. Smith returned an interception by quarterback Jeff Tuel, that was intended for wide receiver T. J. Graham, for a 100-yard touchdown. The touchdown became Smith's first career pick six. In Week 13, he recorded a season-high tying five solo tackles during a 35–28 loss to the Denver Broncos. He completed the 2013 season with 47 combined tackles (43 solo), 13 pass deflections, two interceptions, and a touchdown in 16 games and 16 starts. Pro Football Focus gave Smith an overall grade of 76.7, which ranked 44th among all qualifying cornerbacks in 2013.
The Kansas City Chiefs finished second in the AFC West with an 11–5 record and earned a wildcard berth. On January 4, 2014, Smith started in his first career playoff game and recorded four combined tackles and a pass deflection in the a Chiefs' 45–44 loss at the Indianapolis Colts in the AFC Wildcard Game.
Head coach Andy Reid demoted Smith after he was arrested for a DUI in June (see Legal troubles). He competed against Marcus Cooper, Ron Parker, and Chris Owens during training camp. Smith was named a starting cornerback, along with Marcus Cooper, to start the regular season. On September 29, 2014, Smith made a season-high two pass deflections, three solo tackles, and an interception during a 41–14 victory against the New England Patriots in Week 4. The following week, he collected a season-high six solo tackles and two pass deflections in the Chiefs' 22–17 loss at the Kansas City Chiefs in Week 5. He finished the season with 50 combined tackles (47 solo), a career-high 16 passes defended, and an interception in 16 games and 16 starts.
On July 24, 2015, the NFL announced that Smith would be suspended for the first three games of the 2015 season after pleading guilty to a DUI charge earlier in April. Defensive coordinator Bob Sutton named Smith and rookie first round pick Marcus Peters the starting cornerbacks with Phillip Gaines replacing Smith for the first three games.
On November 1, 2015, Smith collected a season-high five solo tackles and a season-high three pass deflections during a 45–10 victory against the Detroit Lions in Week 5. In Week 17, he recorded a season-high six combined tackles in the Chiefs' 23–17 win against the Oakland Raiders. Smith completed the season in 2013 with 45 combined tackles (40 solo), 12 pass deflections, and two interceptions in 13 games and 13 starts.
The Kansas City Chiefs finished the season second in the AFC West with an 11–5 record. On January 9, 2016, Smith started in the AFC Wildcard Game and recorded six solo tackles, two pass deflections, and intercepted a pass by Brian Hoyer as the Chiefs routed the Houston Texans 30–0. The following week, he made four combined tackles in a 27–20 loss at the New England Patriots in the AFC Divisional Round.
Smith became an unrestricted free agent for the second time in his career after the 2015 season and drew interest from multiple teams after the New York Giants signed top free agent cornerback Janoris Jenkins. It was reported he received major interest from the Oakland Raiders, San Francisco 49ers, and Los Angeles Rams.
