Miles was born to parents Mary and Gerald in February 1992. He grew up in the rural New South Wales town of Howlong, 30 kilometres north-west of Albury. Miles attended school at Albury High School in the New South Wales/Victoria border town. He played club football with Howlong in the Hume Football League.
In 2009 and 2010 Miles played TAC Cup football for the Murray Bushrangers, appearing in 13 and 11 matches respectively. He finished both seasons in second place in the club's best and fairest award. In 2010 he was also the club's club's vice-captain. In addition, he played matches for the NSW/ACT Rams in the same competition in 2010 and served as the team's captain during this time. He was selected in the TAC Cup team of the year in 2010.
Miles played representative state football for NSW/ACT at under-16 and under-18 levels, captaining both teams. He was selected as an under-18 All-Australian following a stellar national carnival in 2010.
Miles was originally recruited to the newly formed GWS Giants through zoning concessions. He signed his first contract with the club while still in high school in June 2010, opting out of a potential nomination for the AFL draft in the process.
Miles would go on to train and play for the club in matches prior to its introduction to the AFL in 2012.
He played his first AFL game in Round 4, 2012 in a loss to Adelaide at AAMI Stadium. He recorded 15 disposals, eight marks and six tackles in the match. He recorded an impressive 27 disposals in his next match, in Round 17 against Fremantle. He managed seven appearances in an injury-riddled debut season, recording averages of 18 disposals and five marks.
Miles would manage just three AFL appearances in 2013, with averages of 13 disposals four tackles and four marks. He did however kick his first career goal in a Round 9 loss to Hawthorn at York Park.
At the conclusion of the 2013 season the Giants decided not to offer Miles a new contract. Efforts to move him during the trade period all failed and he was later de-listed by the club. He had played ten games across two seasons.
Miles was subsequently drafted by the Richmond Football Club with the club's second pick and 27th pick overall in the 2014 Rookie Draft.
In May 2014, Miles was upgraded to Richmond's senior list and played his first senior game for Richmond in Round 12, 2014. He recorded 18 disposals and eight clearances for the match Miles impressed early, with Tigers coach Damien Hardwick pleasantly surprised by Miles' substantial contributions to the team. Over his first six matches Miles lead all Richmond players for contested possessions and placed third in the league for clearances. He didn't miss another game that season, including appearing in the club's losing elimination final to Port Adelaide. He finished the season placed fifth at the club for average disposals (24.4) and second in total clearances despite playing in just 13 matches. His per game clearance rate (6.6) was the sixth best across all league players that season.
Miles entered the 2015 season firmly in the club's best 22. This would remain the case throughout the year, with Miles playing his first full season of matches, including a second straight finals series. He twice matched his then career-high 30 disposals in Rounds 6 and 18 matches against North Melbourne and Hawthorn. Miles was one of the club's best in its elimination final defeat at the hands of North Melbourne. He recorded a team high 22 disposals and team high 9 clearances on the day. At the end of the season Miles led the club for clearances (135) and placed third for total disposals (544). He also recorded the second-most free kicks drawn of any player in the league that season. His nine votes received in the year's Brownlow Medal was both a career high and good for third place at the club. In October Miles was awarded the Fred Swift medal for his fourth placed finish in the club's best and fairest count.
Prior to 2016, Miles expressed a need to improve his fitness base. With the reduction in the interchange cap from 120 to 90 per team per game, Miles recognised the need to stay on the field for longer stretches than ever before. His early output in 2016 reflected the struggles that came with this change. He missed his first game since his Richmond debut when he was dropped ahead of the team's Round 4 clash with West Coast. He returned to the team after missing just one match though, recording 25 disposals and a goal in Round 6's ANZAC Day eve match against Melbourne. Though he recorded a career best 31 disposals in Round 8, Miles found consistency hard to come by in 2016. In Round 19 he recorded his lowest disposal match since joining Richmond, picking up just 11 during his side's huge loss to his old club Greater Western Sydney. He was dropped again prior to Round 22, and did not return to the senior side for the final match of the season. Miles placed sixth in the club's best and fairest count in 2016. He dropped to eighth at the club for average disposals (22.7) and third (92) for total clearances in 2016.
As with the previous season, Miles' 2017 pre-season saw him training to improve his aerobic fitness in addition to adding versatility to his game. But with the off-season addition of Josh Caddy and Dion Prestia, Miles was squeezed out of the Richmond midfield brigade, forced to sit out the season opening match for the first time in three years. He remained in the club's reserves side for the following six weeks. Richmond VFL coach Craig McRae referred to Miles as "an AFL player waiting for an opportunity" after he recorded 35 disposals and two goals in one such match. He made his return to AFL football in Round 7, called to the senior side to play the reigning premier Western Bulldogs. His stay was short-lived however, being dropped again in Round 8. Miles returned once more for a single game in Round 9, this time recording 15 disposals, one tackle and two marks in the loss to his former team the GWS Giants. After being dropped for Round 10 another two months of VFL football awaited, where he was a consistent performer including a three week run of 35, 34 and 32 disposals. In Round 17 he once more returned to senior football, recording 24 disposals, eight marks and four tackles in Richmond's win over the Brisbane Lions.
Miles is contracted to Richmond until the end of the 2017 season.Statistics are correct to the end of round 19, 2017
Miles is a practicing Christian. He has two older brothers, Lance and David.