The 2018 Speed Energy Stadium Super Trucks were the sixth season of the Stadium Super Trucks series. The season consisted of 20 races; it began on January 27, 2018 at Lake Elsinore Diamond and concluded on January 20, 2019 at Foro Sol in conjunction with the 2019 Race of Champions.

With a series-high six wins and 540 total points, Matthew Brabham won his first championship. Gavin Harlien finished second in the standings with 490 points and five wins.

The season began at the Lake Elsinore Diamond, where the 2017 finale had been held. Apdaly Lopez won the Feature event, but confusion arose in the days following the race as multiple drivers took the Joker Lap on the final lap, which is not allowed per series rules. After video review by series officials, Bill Hynes – who ran the Joker on the penultimate lap – was declared the winner, though Lopez was allowed to keep his win. Matthew Brabham, who finished seventh, was also revealed to have utilized the same strategy as Hynes, and had his finishing position upgraded to second alongside Jeff Hoffman.

A tripleheader at Australia's Adelaide Street Circuit followed. In the first race, rookie Cole Potts took advantage of Robby Gordon's transmission problem and Brabham locking his brakes entering a turn to win his first SST race. Gordon rebounded to win the second, while Brabham won the final round; Gordon had been in position to win the third race when he entered the final corner too deep, allowing Brabham to capitalize and win. Behind him, Gavin Harlien's truck landed off a jump at a poor angle, resulting in a broken right rear wheel that caused him to hit the wall. Harlien continued to accelerate until he crossed the start/finish line to finish sixth.

At the Grand Prix of Long Beach, the first race was stopped after Apdaly Lopez rolled his truck with 17 minutes left; race officials chose not to resume the event and leader Harlien was declared the winner, scoring his maiden series victory. Series commentator Sean Sermini criticized the decision during the broadcast, calling it "Very upsetting." Brabham won the second round of the weekend.

In May, the series returned to Australia to race at Barbagallo Raceway in Perth. Matt Nolan, running his first points race, flipped while jumping on a ramp in the first event, causing his truck's left rear wheel to come off; the wheel eventually hit a vacant spectator bridge. The incident eventually spurred the Confederation of Australian Motor Sport (CAMS) to suspend the series from CAMS-sanctioned races for safety concerns, though SST officials were not notified of the news until July. The weekend concluded with Arie Luyendyk Jr. and Jeff Hoffman scoring their first series wins, while Brabham recorded the overall weekend win.

Harlien and Luyendyk won at Detroit, the former holding off Aaron Bambach and Luyendyk for the win in the first race. Six laps into the second round, Luyendyk was the race leader when the red flag came out for Paul Morris' wreck in turn three that sent him airborne and onto his truck's roof after hitting a tire barrier.

The series returned to Texas Motor Speedway for a second year in June. Japanese rally driver E. J. Chiba made his series debut, while Gordon returned for the weekend after missing the Detroit weekend to race in the Baja 500. On lap 16 of 18, Harlien passed Morris for the lead and eventually won Race One, while Brabham took advantage of the field fighting among themselves for position to win Race Two.