2011-2012: Professional debut

Harris's first appearance in a professional tournament was at the Australia F7 in September 2011, where he made the quarterfinal before losing to Alex Bolt.

Harris lost in round 1 of the 2012 Australian Open qualification to Denys Molchanov, before competing in three Future tournaments in Australia. His best result being a quarterfinal in Australia F4 in March where he retired whilst playing Maverick Banes. Harris played only one more tournament in 2012, the Great Britain F10 in July, where he lost in the second round.

2013

He signed a National Letter of Intent with Oklahoma Sooners to participate in 2013.^[1]

Harris successfully returned to competition in May 2013, where he made the final of the Thailand F2, losing to Saketh Myneni of India. The following week, he made the semifinal of the Thailand F3, losing to fellow Australian Adam Feeney in straight sets. Throughout June and July, Harris competed in Futures throughout Europe, his best performance being a quarterfinal in Belgium F4, before winning his first title in October in Texas at the USA F27 against Dennis Nevolo.

2014

Harris retired from round 1 of the qualification for the 2014 Brisbane International before competing in the Men's qualifying of the 2014 Australian Open, where he made round 2. Harris didn't play again until June, where he played in 5 futures in the USA. The best result was at the F17 in Oklahoma City, where he was runner-up to Jared Donaldson.

2015

Harris commenced the 2015 season at the Onkaparinga Challenger, where he qualified and registered his first Challenger main draw win, defeating Hiroki Moriya 7–5, 6–1. He made it to the semi-final, before losing to Marcos Baghdatis. This increased Harris's ATP ranking 157 places to a career high of No. 497. Harris made the second round of Australian Open qualifying. This was the last match Harris played for almost 2 years.

2017-2018: Return to the Tour

In January 2017, Harris returned to tennis gaining a wildcard into the 2017 Canberra Challenger. He defeated Thomas Fancutt in round 1, before losing to Jan-Lennard Struff in a close 3-set match. Harris did not play again until June 2017 on the ITF Futures circuit in USA. In July, he lost in qualifying rounds of two Canadian Challenger events. In September, Harris returned to Australia and won his second ITF title at Toowoomba in October.

Harris spend the 2018 year on the ITF Futures and ATP Challenger Circuits across Australia and United States of America. His best performances were semifinal results at Launceston in February, Australia F4 in March, USA F19 in July and USA F23 in August.

2019: First Challenger finals, top 200

In February, Harris reached his first ATP Challenger Tour final at Chennai Open Challenger. The result led to a career-high ranking.^[2] In May, Harris reached the final of Busan Challenger, further improving his ranking.^[3] In August, Harris lost in the first round of 2019 US Open – Men's singles qualifying.

2020: Grand Slam debut

Harris was awarded a wildcard into the 2020 Australian Open, where he lost in straight sets to 8th seed Matteo Berrettini. Harris ended 2020 with a singles rank of 229.

2021: First ATP singles win

Harris commenced 2021 at the 2021 Murray River Open, where he recorded his first ATP main draw win against Taro Daniel. Harris lost in the second round of the 2021 Australian Open – Men's singles qualifying. This was the final tournament Harris played for the year.

2022: Three Challenger doubles titles

Harris lost in the first round of qualifying at the 2022 Australian Open.^[4]

2023: Maiden ATP doubles final

At the 2023 Los Cabos Open he reached his maiden ATP final with Dominik Koepfer.^[5]

Doubles: 2 (2 titles)

More information Result, Year ...

Result	Year	Tournament	Surface	Partner	Opponents	Score
Win	2012	French Open	Clay	Nick Kyrgios	Adam Pavlásek Václav Šafránek	6–4, 2–6, [10–7]
Win	2012	Wimbledon	Grass	Nick Kyrgios	Matteo Donati Pietro Licciardi	6–2, 6–4

Close

Doubles: 1 (1 runner-up)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Aug 2023	Los Cabos Open, Mexico	250 Series	Hard	Dominik Koepfer	Santiago González Édouard Roger-Vasselin	4–6, 5–7

Close

Singles: 9 (2–7)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Jun 2013	Thailand F2, Bangkok	Futures	Hard	Saketh Myneni	6–7(4–7), 1–6
Win	1–1	Oct 2013	USA F27, Mansfield	Futures	Hard	Dennis Nevolo	6–4, 7–6(7–5)
Loss	1–2	Jun 2014	USA F17, Oklahoma City	Futures	Hard	Jared Donaldson	3–6, 2–6
Win	2–2	Oct 2017	Australia F6, Toowoomba	Futures	Hard	Jason Kubler	6–4, 6–0
Loss	2–3	Nov 2017	Vietnam F3, Thủ Dầu Một City	Futures	Hard	Arjun Kadhe	5–7, 3–6
Loss	2–4	Feb 2019	Chennai, India	Challenger	Hard	Corentin Moutet	3–6, 3–6
Loss	2–5	May 2019	Busan, South Korea	Challenger	Hard	Ričardas Berankis	6–7(5–7), 2–6
Loss	2–6	Oct 2019	Traralgon, Australia	Challenger	Hard	Marc Polmans	5–7, 3–6
Loss	2-7	Mar 2022	M25 Bendigo, Australia	World Tennis Tour	Hard	Li Tu	3–6, 1–6

Close

Doubles: 15 (8–7)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Jul 2012	Great Britain F10, Ilkley	Futures	Grass	Andrew Whittington	Lewis Burton Edward Corrie	1–6, 1–6
Win	1–1	Oct 2019	Ningbo, China	Challenger	Hard	Marc Polmans	Alex Bolt Matt Reid	6–0, 6–1
Win	2–1	May 2022	M25 Prague	World Tennis Tour	Clay	Daniel Cukierman	Filip Duda Peter Heller	6–0, 6–3
Win	3–1	May 2022	Little Rock, USA	Challenger	Hard	Christian Harrison	Robert Galloway Max Schnur	6–3, 6–4
Win	4–1	Jul 2022	Rome, USA	Challenger	Hard (i)	Enzo Couacaud	Ruben Gonzales Reese Stalder	6–4, 6–2
Win	5–1	Nov 2022	Matsuyama, Japan	Challenger	Hard	John-Patrick Smith	Toshihide Matsui Kaito Uesugi	6–3, 4–6, [10–8]
Loss	5–2	Nov 2022	Kobe, Japan	Challenger	Hard (i)	John-Patrick Smith	Shinji Hazawa Yuta Shimizu	4–6, 4–6
Loss	5–3	Jan 2023	Canberra, Australia	Challenger	Hard	John-Patrick Smith	André Göransson Ben McLachlan	3–6, 7–5, [5–10]
Win	6–3	Feb 2023	Tenerife, Spain	Challenger	Hard	Christian Harrison	Luke Johnson Sem Verbeek	7–6(8–6), 6–7(4–7), [10–8]
Loss	6–4	May 2023	Gwangju, South Korea	Challenger	Hard	John-Patrick Smith	Evan King Reese Stalder	4–6, 2–6
Win	7–4	Jun 2023	Tyler, United States	Challenger	Hard	Alex Bolt	Evan King Reese Stalder	6–1, 6–4
Loss	7–5	Jul 2023	Chicago, United States	Challenger	Hard	Chung Yun-seong	Mikelis Libietis Skander Mansouri	6–7(5–7), 3–6
Win	8–5	Sep 2023	Cary, United States	Challenger	Hard	Rinky Hijikata	William Blumberg Luis David Martinez	6–4, 3–6, [10–6]
Loss	8–6	Oct 2023	Málaga, Spain	Challenger	Hard	John-Patrick Smith	Julian Cash Robert Galloway	5–7, 2–6
Loss	8–7	Nov 2023	Kobe, Japan	Challenger	Hard	Nam Ji-sung	Evan King Reese Stalder	6–7(3–7), 6–2, [7–10]

Close

Singles

Doubles