Lewis began racing at seven years old, competing in regional karting series under the guidance of Michael Andretti. In 2002, he won the Stars of Karting Regional Championship, and two years later finished as runner-up in the World Karting Association National Series. From 2007, Lewis competed at the Skip Barber Racing School, winning 14 of 26 races over three years. He made a brief Star Mazda Championship appearance in 2012 with Team GDT, contesting one event at Toronto.
Lewis entered the Continental Tire Sports Car Challenge in 2013, marking his first step into sports car and touring car racing. The following year he scored his first series win in the Street Tuner class for BERG Racing at Indianapolis.
In 2015, Lewis achieved a double title, winning the Pro-Am class title in both the Lamborghini Super Trofeo North America and the Lamborghini Super Trofeo World Final. This success led to his entry into the Lamborghini GT3 Junior Program for 2016.
For 2016, Lewis joined Change Racing for the IMSA SportsCar Championship alongside co-driver Spencer Pumpelly, while also representing Lamborghini in the GT3 Junior Program alongside Richard Antinucci, Edoardo Piscopo, and Cedric Sbirrazzuoli. Change Racing achieved a best finish of fifth that season at VIR and Mosport.
In 2017, Lewis claimed his first IMSA SportsCar Championship victory with Change Racing, taking GTD class honors at VIR in August.
For 2018, Lewis signed with P1 Motorsports for the IMSA Prototype Challenge alongside Matt Dicken, while also contesting endurance races with Paul Miller Racing at Sebring and Petit Le Mans. In his opening race with Paul Miller Racing at Sebring, the team won the class outright, giving Lewis his first 12 Hours of Sebring class victory. Lewis and co-driver Madison Snow also won the Pro-class title in the Lamborghini Super Trofeo North America that season, a title they defended successfully in 2019, before Lewis took the Pro-Am class title in 2020.
In 2020, Lewis took his first class victory at the 24 Hours of Daytona with Paul Miller Racing. He also returned to the Michelin Pilot Challenge that season with Canadian team Motorsport in Action, taking one victory. His concurrent Lamborghini Super Trofeo commitments occasionally required him to drive for three different teams in three different cars across a single race weekend.
In 2021, Lewis joined K-Pax Racing's two-car effort in the GT World Challenge America Pro class alongside Lamborghini factory driver Giovanni Venturini, scoring their first win together at Circuit of the Americas in May.
Lewis returned to Paul Miller Racing ahead of the 2023 IMSA SportsCar Championship season, continuing the relationship with the team that had produced class victories at Sebring and Daytona earlier in his career.