2013–2017: Career beginnings on ITF and Challenger Tour

Walkin made his ITF debut in March 2013 at the Australia F4, where he made the second round. It was his only singles tournament of the year.

In 2014 and 2015 Walkin played on the ITF in Australia and Europe, with the second round being he best performance in singles and semi-finals in doubles.

In September 2016 Walkin reached the quarter-final of the Australia F5.

In October 2016 Walkin debuted on the ATP Challenger Tour after he qualified for Traralgon ATP Challenger.

In February 2017 Walkin reached his first ITF finals in doubles in Anning, China. Walkin also won his first ITF title in Anning, China, partnered with Thomas Fancutt. Walkin played his last match on the ITF circuit in April 2017 for almost two years.

2019–2021

In February 2019 following a two-year injury lay off, Walkin played his first match on the ITF circuit since April 2017 and throughout 2019, made 8 ITF doubles finals. In May 2019, Walkin reached his first singles ITF final in M15 Cancun, which saw him re enter the ATP top 1000 rankings. Walkin returned to Australia and played several ITF and challenger events, finishing 2019 with a singles ranking of 782 and a doubles rank of 334. Walkin also competed in the Australian Open Wildcard Playoffs in 2019 losing to eventual winner J.P Smith

Walkin started 2020 playing in the North American ITF Circuit, achieving a semi-final run at Cancun, Mexico, before the COVID-19 pandemic stopped play in March 2020.

2022: ATP debut

Walkin began 2022 at the 2022 Traralgon International following yet another injury lay off. He reached the second round. Walkin made his ATP Tour debut at the 2022 Adelaide International 2, playing doubles alongside Harry Bourchier. Walkin also competed in the singles qualifying event.^[2]

Singles: 2 (0 title)

Result	W–L	Date	Level	Tournament	Surface	Opponent	Score
Loss	0–1	Jun 2019	M15	Cancun, Mexico	Hard	Jordi Arconada	5–7, 4–6
Loss	0–2	Apr 2023	M25	Jakarta, Indonesia	Hard	Yankı Erel	3–6, 0–6

Doubles: 27 (16 titles)

Result	W–L	Date	Level	Tournament	Surface	Partner	Opponents	Score
Loss	0–1	Feb 2017	M15	Anning, Yunnan, China	Hard	Thomas Fancutt	Marco Bortolotti Nino Serdarušić	6–7, 6–3, [8–10]
Winner	1–1	Mar 2017	M15	Anning, Yunnan, China	Hard	Thomas Fancutt	Bai Yan Zhao Cai	6–4, 6–4
Winner	2–1	Mar 2019	M25	Mildura, Australia	Grass	Calum Puttergill	Brydan Klein Scott Puodziunas	7–6, 6–7 [18–16]
Winner	3–1	Mar 2019	M25	Mornington, Victoria, Australia	Clay	Calum Puttergill	Thomas Fancutt Dane Sweeny	6–1, 7–5
Winner	4–1	Mar 2019	M25	Mornington, Victoria, Australia	Clay	Calum Puttergill	Aaron Addison Karunuday Singh	1–6 6–3 [10–8]
Winner	5–1	May 2019	M15	Cancun, Mexico	Hard	Matthew Christopher Romios	Alexios Halebian Paul Oosterbaan	6–2, 2–6, [10–8]
Loss	5–2	Jul 2019	M15	Cancun, Mexico	Hard	Felix Corwin	Jaimee Floyd Angele Ronan Joncour	6–3, 3–6, [8–10]
Loss	5–3	Jul 2019	M15	Cancun, Mexico	Hard	Tyler Mercier	Joshua Ortlip Breno Souza Plentz	6–3, 6–7, [5–10]
Loss	5–4	Aug 2019	M15	Cancun, Mexico	Hard	Isaac Stoute	Shintaro Mochizuki Thiago Agustin Tirante	6–7, 7–5, [4–10]
Winner	6–4	Sep 2019	M25	Cairns, Australia	Hard	Calum Puttergill	Vladyslav Orlov Rhett Purcell	6–4, 5–7, [10–5]
Loss	6–5	Feb 2020	M15	Cancun, Mexico	Hard	Gabriel Petit	Simon Carr Ajeet Rai	4–6, 2–6
Winner	7–5	Feb 2020	M15	Cancun, Mexico	Hard	Igor Marcondes	Francisco Comesaña Alejo Lorenzo Lingua Lavallen	6–3, 6–4
Loss	7–6	Dec 2021	M15	Cancun, Mexico	Hard	Constantin Bittoun Kouzmine	Arklon Huertas del Pino Conner Huertas del Pino	4–6, 4–6
Win	8–6	Feb 2022	M25	Bendigo, Australia	Hard	Calum Puttergill	Blake Ellis Tristan Schoolkate	6–2, 6–3
Loss	8–7	May 2022	M15	Antalya, Turkey	Clay	Matthew Christopher Romios	Vladimir Korolev Maxim Ratniuk	6–7(3–7), 6–4, [5–10]
Win	9–7	Jun 2022	M25	Kiseljak, Bosnia & Herzegovina	Clay	Matthew Christopher Romios	Mattia Bellucci Remy Bertola	3–6, 6–4, [10–6]
Loss	9–8	Jun 2022	M15	Bytom, Poland	Clay	Matthew Christopher Romios	Jakub Mensik Olaf Pieczkowski	6–7(3–7), 5–7
Win	10–8	Jul 2022	M15	Velenje, Slovenia	Clay	Constantin Bittoun Kouzmine	Jiri Barnat Filip Duda	6–1, 6-2
Win	11–8	Aug 2022	M25	Padova, Italy	Clay	Jason Taylor	Duje Ajdukovic Frane Nincevic	7–6(7–3), 6-0
Win	12–8	Aug 2022	M25	Poznan, Poland	Clay	Jason Taylor	Michal Dembek Georgii Kravchenko	7–5, 7–5
Loss	12–9	Oct 2022	M25	Rodez, France	Hard	Zvonimir Babić	Mats Hermans Mick Veldheer	3–6, 4–6
Win	13–9	Oct 2022	M25	Jakarta, Indonesia	Hard	Thomas Fancutt	Sun Fajing Seita Watanabe	4–6, 6–3, [10–6]
Loss	13–10	Mar 2023	M25	Canberra, Australia	Clay	Matthew Christopher Romios	Taisei Ichikawa Daisuke Sumizawa	6–7(6–8), 7–5, [3–10]
Win	14–10	Apr 2023	M25	Jakarta, Indonesia	Hard	Matthew Christopher Romios	Ray Ho Parikshit Somani	7–5, 6–4
Win	15–10	May 2023	M15	Brcko, Bosnia & Herzegovina	Clay	George Goldhoff	Lukas Pokorny David Pichler	7–6(7–4), 6–3
Win	16–10	Jun 2023	M25	Kiseljak, Bosnia & Herzegovina	Clay	Matthew Christopher Romios	Stefan Latinovic Andrej Radojicic	6–2, 6–3
Loss	16–11	Jun 2023	M15	Sarajevo, Bosnia & Herzegovina	Clay	Matthew Christopher Romios	Juan Bautista Otegui Matias Zukas	6–7(0–7), 3–6