On April 26, 2013, Smith re-signed with the Bengals. It was reported by NFL.com's Ian Rapoport that Smith agreed to a three-year, $18 million contract during the second round of the 2013 NFL Draft. He started in games 1-11 and 13–16 at right tackle, and came off bench in week 12, helping the Bengals rank tied for sixth in scoring and tenth in net offense. He was a key cog in pass protection, allowing only one sack over games 11–14, tying a team record for fewest sacks allowed in a four-game span. On September 16 against the Pittsburgh Steelers, he helped the offensive line allow no sacks with 407 net yards. He aided a blocking effort in week 6 at Buffalo in which the Bengals offense tallied a season-high in total net yards with 483 yards, including season-highs in both rushing (165) and passing (318). On October 27 against the New York Jets, he contributed to pass protection allowing only one sack for two yards as Andy Dalton threw for a career-best five touchdown passes. In week 14 against Indianapolis, he helped keep Dalton sack-free for the third straight game and supported a 155-yard rushing effort, and Dalton was named AFC Offensive Player of Week with a 120.5 passer rating. In the wild card playoff game on January 5, 2014, he contributed to a 439-yard offensive output against the San Diego Chargers.