George has played for Saracens since 2009 after training in the Saracens Academy.
2009–10 season
In the 2009–10 season George made his debut for the Saracens first team. However this was the only appearance he was to make in the season. He continued his development playing for the Saracens Storm in the A league.
2010–11 season
The 2010–11 season was George's first season for the Saracens first team. He played most of the season as an understudy to Schalk Brits who he described as "He is a fantastic role model. I admire his approach to life and rugby and I have so much to learn from him". In the season he made 20 appearances and scored two tries, helping Saracens to secure a home semi-final in the Aviva Premiership. He was a replacement as Saracens won their first Premiership title.
2015 Saracens
George started the 2015 Aviva Premiership Final, and was the centre of added pressure and attention due to his promotion to the England squad. George responded well and starred during the match, running in one try from over 30-metres out, and passing the ball to Chris Wyles for his try.
2020 Saracens
In July 2020, George signed a new three-year contract with Premiership side Saracens. However, his deal implies that he would play in Championship next season, after his club was relegated following breach of salary cap.
International career 2015 onwards
On 29 May 2015 George was promoted to England's extended 50-man training squad for the 2015 Rugby World Cup. George replaced 66-test veteran Dylan Hartley in the squad after Hartley was suspended for head-butting George in a Saracens vs Northampton Saints fixture. George was announced in Stuart Lancaster's 31-man squad for the 2015 Rugby World Cup just 5 days after making his international debut against France during the World Cup Warm Ups, replacing Tom Youngs in the 48th minute. In January 2016, George was announced in Eddie Jones' first senior England squad for the 2016 Six Nations Championship and made his Six Nations debut against Scotland, replacing captain Dylan Hartley in their 15–9 victory on 6 February 2016. In 2017, he was selected as a member of the 41-man British and Irish Lions 2017 squad. George played six matches on the tour including all four tests, one against the Maori All Blacks and three against the All Blacks. The 32-10 win against the Maori All Blacks was his first international start having played all 17 of his England tests coming off the bench, a world record for most tests without a start. George played the full 80 minutes in the second test against New Zealand, setting up Conor Murray's winning try.