George was born in Paddington Australia to English parents on 4 June 1997 and grew up in Berowra, New South Wales Australia.

He attended Asquith Boys High School and played youth football for APIA Leichhardt Tigers.

In 2013, he spent a month training at Colchester United after winning a scholarship award in Australia.

In October 2014, 17-year-old George Blackwood made his first appearance with Sydney FC‘s senior squad. He scored his first goal for the club on 16 March 2016.

At the end of the 2016/17 season, Blackwood refused a new contract from Sydney FC 

In July 2017, he signed for Adelaide United where he scored his first professional goal for the Adelaide in the Round of 16 of the 2017 FFA Cup. He made an appearance in the 2017 FFA Cup Final on 21 November 2017 against his former club Sydney FC.

On 26 August 2020 he was released by the club to pursue a new opportunity and on 6 September 2020, he moved to England where he signed with Oldham Athletic on a two-year deal. He scored his first goal for Oldham on 3 November 2020.

At the end of season 2020/2021, George returned to Australia after agreeing to terminate his contract with Oldham Athletic.

On 2 August 2021, he returned to Adelaide United signing a two-year deal. In his first game back for the club, Blackwood scored a penalty in a Round of 32 match of the 2021 FFA Cup,

On 9 November 2023, he moved to Indonesia where he joined Bhayangkara FC in Liga 1.

In season 2014/2015 George also represented Australia at under-20 level and at under-23 level in the period 2015-2019.