[19] Brown won the silver medal in his Junior Grand Prix debut in France and placed sixth in his second JGP event in Japan.

He finished 9th in his senior national debut at the 2011 U.S. Championships with an impressive performance despite not attempting a triple Axel, which he had decided to put off due to a growth spurt.

He was sent to the 2013 World Junior Championships, where he placed third in the short program and first in the free skate after landing two triple Axels for the first time in his career.

[14][29] Brown won the silver medal in his senior international debut at the 2013 Nebelhorn Trophy in Oberstdorf, Germany.

In November 2013, he competed at a Grand Prix event in Paris, the 2013 Trophée Éric Bompard, and won the bronze medal.

[35] Brown began the 2014–15 season at the 2014 Nebelhorn Trophy, an ISU Challenger Series event, and won the gold medal after placing first in both programs.

The USFSA denied his petition and named Adam Rippon, Max Aaron, and Nathan Chen, whom Grant Hochstein later replaced due to injury.

[28][46] Brown began his season at 2016 Lombardia Trophy, where he won the silver medal after placing second in the short program and first in the free skate.

Ranked fourth in the short and third in the free, he won the bronze medal, achieving his first podium finish at a senior-level ISU Championship.

Competing at a second Challenger event, the 2018 CS Golden Spin, he won the gold medal after placing second in the short program and first in the free skate.

In his free skate, Brown avoided popping his opening quad Salchow for the first time that season, though it was deemed underrotated, and he stepped out of the landing.

[58] At the 2019 World Championships, he placed second in the short program, with a new personal best score of 96.81, winning a silver small medal.

Brown popped his planned triple Axel to a single in the short program, placing fourth in that segment.

[62] In the free skate, Brown performed all his jumps successfully other than doubling a planned triple loop, placing second in that segment to take the silver medal.

[64] At the 2020 Four Continents Championships, Brown placed third in the short program with a clean skate, defeating several skaters who performed at least one quadruple jump.

[68] As a result, Brown made his season debut at the 2021 U.S. Championships in Las Vegas, placing third in the short program with a clean skate.

He placed third in the short program and eighth in the free skate, with his total score ranking sixth among the men.

[77] Attempting a quad Salchow in the free skate, he two-footed the landing but was credited with full rotation for the first time.

[78] Brown's results qualified him to the Grand Prix Final, but it was subsequently canceled due to restrictions prompted by the Omicron variant.

[79] Traveling to attend the 2022 U.S. Championships with coach Tracy Wilson proved to be an odyssey for Brown due to five different flight cancellations that had him in transit for thirty-three hours, culminating in a rental car trip from Atlanta to Nashville.

Normally regarded as one of the best spinners in the world, on one of his three free skate spins, he lost two levels, which made the difference between third and fourth overall as he finished 0.38 points behind bronze medalist Vincent Zhou.

[81] Per the selection criteria for the American Olympic team, Zhou and national champion Nathan Chen were guaranteed berths, with the third to be decided between Brown and 17-year-old surprise silver medalist Ilia Malinin.

"[81] Competing at the 2022 Winter Olympics in the men's event, Brown skated a clean short program and placed sixth with a new personal best score of 97.24.

[86] Brown, by his own later admission, had not intended to compete further following the Olympic season, and moved out of his longtime Toronto apartment to relocate back to the United States.

However, after accepting an invitation to compete at the Japan Open in the fall, he prepared a new free skate to "The Impossible Dream" from Man of La Mancha.

He placed fifth at the Japan Open, and found his competitive drive reawakened by the experience, at which point he decided to return for the second half of the season starting with the national championships.

[87] At the 2023 U.S. Championships in San Jose, Brown placed second in the short program, 10.11 points behind favorite Ilia Malinin.

Brown said that he felt he had faced down "demons" by competing successfully in San Jose, the site of his failure to qualify for the 2018 Olympic team that he personally considered the low point of his career.

[92][93] Brown again began his season at the Japan Open, coming fifth in the men's segment while Team North America won the silver medal.

Going on to compete on the Grand Prix circuit for the first time in three years, Brown finished eighth at 2024 Skate Canada International after struggling through both of his programs.