Rubin played for the John McEnroe Tennis Academy on Randalls Island in Manhattan.
By the age of seven, Rubin was competing in 12-and-under events, and he was winning international competitions by the time he was eleven.
 In 2010, he made it to the finals at Les Petits As in Tarbes, France.
In 2011, when Rubin was 15, John McEnroe called him "the most talented player we've come across."
He also won the Copa Del Café, a Junior ITF tournament in Costa Rica, in 2012.

As a junior, Rubin reached as high as no.
6 in the International Tennis Federation's world junior ranking and no.
1 in the United States in 2014.

He qualified for the boys' singles tournament at Wimbledon in July 2014, and won the tournament in the first all-American final there since 1977.
He was the first American boy to win Wimbledon since Donald Young in 2007.
He had played only one other event in 2014 before Wimbledon at the French Open, where he lost in the second round.

The month after hoisting the trophy at Wimbledon, Rubin played in and won the 2014 U.S. Tennis Association's Boys 18s National Championships in both singles and doubles (with close friend Stefan Kozlov).
The latter success came with two big bonuses of main-draw wild cards into the singles and doubles events at the US Open.
Rubin played for the John McEnroe Tennis Academy on Randalls Island in Manhattan. By the age of seven, Rubin was competing in 12-and-under events, and he was winning international competitions by the time he was eleven.  In 2010, he made it to the finals at Les Petits As in Tarbes, France. In 2011, when Rubin was 15, John McEnroe called him "the most talented player we've come across." He also won the Copa Del Café, a Junior ITF tournament in Costa Rica, in 2012.
As a junior, Rubin reached as high as no. 6 in the International Tennis Federation's world junior ranking and no. 1 in the United States in 2014.
He qualified for the boys' singles tournament at Wimbledon in July 2014, and won the tournament in the first all-American final there since 1977. He was the first American boy to win Wimbledon since Donald Young in 2007. He had played only one other event in 2014 before Wimbledon at the French Open, where he lost in the second round.
The month after hoisting the trophy at Wimbledon, Rubin played in and won the 2014 U.S. Tennis Association's Boys 18s National Championships in both singles and doubles (with close friend Stefan Kozlov). The latter success came with two big bonuses of main-draw wild cards into the singles and doubles events at the US Open.
Noah Rubin (tennis)