Player

Cahill turned professional in 1984. He won his first tour doubles title in 1985 at the Melbourne Outdoor tournament. In 1987, he won his first top-level singles title at New Haven.

Cahill's best singles performance at a Grand Slam event came at the 1988 US Open, where he knocked out Lawson Duncan, Boris Becker, Marcelo Ingaramo (a walkover after Ingaramo withdrew), Martin Laurendeau, and Aaron Krickstein on the way to reaching the semifinals, where he lost to eventual champion Mats Wilander.

In 1989, Cahill finished runner-up in men's doubles at the Australian Open partnering fellow Aussie Mark Kratzmann. Also with Kratzmann, Cahill won the ATP Championships in Cincinnati.

Cahill was a member of the Australian team which reached the final of the Davis Cup in 1990. The team lost 3–2 to the United States in the final. Cahill compiled a 6–4 career Davis Cup record (4–0 in doubles and 2–4 in singles).

Cahill won his last tour singles title in 1991 at San Francisco. His last doubles title came in 1994 in Sydney.

In 1989, Cahill's reached his career peak doubles ranking of world No. 10 and his peak singles ranking of no. 22 in 1989.^[3] After chronic knee injuries and ten operations, he retired from the professional tour in 1995.^[3]

Coach

Since retiring from the tour, Cahill has been a successful tennis coach and guided Lleyton Hewitt to become the second youngest player ever ranked world No. 1.^[3] After Hewitt, Cahill coached Andre Agassi, who under Cahill became the oldest player ever to be ranked world no. 1 in May 2003. Cahill joined the Adidas Player Development Program after Agassi retired in 2006 and has worked with high-profile players, including Andy Murray, Ana Ivanovic, Fernando Verdasco, Daniela Hantuchová, Sorana Cîrstea, and Simona Halep. In 2017 and 2018, he coached Halep to No.1 on the WTA Tour and the 2018 French Open championship. After a year away, Cahill rejoined with Halep in 2020.

In addition to coaching individual players, Cahill was the Australian Davis Cup coach from 2007 until February 2009. He is also an Adidas talent scout and works with promising junior players worldwide.^[4] He is now a member of the Adidas Player Development Program.^[3] With Roger Rasheed, Brad Gilbert, and Paul Annacone, Cahill is a coach at ProTennisCoach.com, an open-access, professional coaching website.^[5] Cahill is also involved with PlaySight Interactive, a sports technology company behind the SmartCourt. Along with Paul Annacone, he heads up PlaySight's Coaching and Player Development team, helping the company to bring its technology to more tennis coaches and players across the world.^[6]

In January 2022, Cahill began coaching tennis player Amanda Anisimova as a trial coach.^[7] He joined Simone Vagnozzi as a coach for Jannik Sinner in July 2022.^[8] The pair won the award for Coach of the Year at the 2023 ATP Awards.

In 2024 Cahill coached Jannik Sinner to win the Australian Open.^[9]

Media

Since 2007, Cahill is a tennis analyst for the global sports network ESPN for three of the four major tennis Grand Slams: the Australian Open, Wimbledon and the US Open. He also works for the Australian television network Channel 7 for the Hopman Cup and Australian Open.^[10]

Singles: 3 (2 titles, 1 runner-up)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Win	1–0	Jul 1988	Gstaad, Switzerland	Grand Prix	Clay	Jakob Hlasek	6–3, 6–4, 7–6(7–2)
Loss	1–1	Jul 1990	Newport, United States	World Series	Grass	Pieter Aldrich	6–7(10–12), 6–1, 1–6
Win	2–1	Feb 1991	San Francisco, United States	World Series	Carpet	Brad Gilbert	6–2, 3–6, 6–4

Close

Doubles: 20 (13–7)

More information Result, No. ...

Result	No.	Date	Tournament	Surface	Partner	Opponents	Score
Win	1.	23 December 1985	Melbourne, Australia	Grass	Peter Carter	Brett Dickinson Roberto Saad	7–6, 6–1
Loss	1.	9 Jun 1986	Queen's Club, London, England	Grass	Mark Kratzmann	Kevin Curren Guy Forget	2–6, 6–7
Loss	2.	13 September 1987	Bordeaux, France	Clay	Mark Woodforde	Sergio Casal Emilio Sánchez	3–6, 3–6
Win	2.	12 October 1987	Sydney Indoor, Australia	Hard (i)	Mark Kratzmann	Boris Becker Robert Seguso	6–3, 6–2
Win	3.	28 December 1987	Adelaide, Australia	Hard	Mark Kratzmann	Carl Limberger Mark Woodforde	4–6, 6–2, 7–5
Win	4.	4 January 1988	Sydney Outdoor, Australia	Grass	Mark Kratzmann	Joey Rive Bud Schultz	7–6, 6–4
Win	5.	25 April 1988	Hamburg, West Germany	Grass	Laurie Warder	Rick Leach Jim Pugh	6–4, 6–4
Win	6.	10 October 1988	Sydney Indoor, Australia	Hard (i)	John Fitzgerald	Marty Davis Brad Drewett	6–3, 6–2
Win	7.	9 January 1989	Sydney Outdoor, Australia	Hard	Wally Masur	Pieter Aldrich Danie Visser	6–4, 6–3
Loss	3.	16 January 1989	Australian Open, Melbourne	Hard	Mark Kratzmann	Rick Leach Jim Pugh	4–6, 4–6, 4–6
Win	8.	12 June 1989	Queen's Club, London, England	Grass	Mark Kratzmann	Tim Pawsat Laurie Warder	7–6, 6–3
Win	9.	2 October 1989	Brisbane, Australia	Hard	Mark Kratzmann	Broderick Dyke Simon Youl	6–4, 5–7, 6–0
Loss	4.	9 October 1989	Sydney Indoor, Australia	Hard (i)	Mark Kratzmann	Scott Warner David Pate	3–6, 7–6, 5–7
Win	10.	26 February 1990	Memphis, Tennessee	Hard (i)	Mark Kratzmann	Udo Riglewski Michael Stich	7–5, 6–2
Win	11.	9 September 1990	Newport, Rhode Island	Grass	Mark Kratzmann	Todd Nelson Bryan Shelton	7–6, 6–2
Win	12.	6 October 1990	Cincinnati, Ohio	Hard	Mark Kratzmann	Neil Broad Gary Muller	7–6, 6–2
Loss	5.	29 October 1990	Paris, France	Carpet	Mark Kratzmann	Scott Davis David Pate	7–5, 3–6, 4–6
Loss	6.	7 January 1991	Sydney Outdoor, Australia	Hard	Mark Kratzmann	Scott Davis David Pate	6–3, 3–6, 2–6
Win	13.	10 January 1994	Sydney Outdoor, Australia	Hard	Sandon Stolle	Mark Kratzmann Laurie Warder	6–1, 7–6
Loss	7.	31 January 1994	Dubai, United Arab Republic	Hard	John Fitzgerald	Todd Woodbridge Mark Woodforde	7–6, 4–6, 2–6

Close

Mixed doubles: 1 (0–1)

More information Result, Year ...

Result	Year	Tournament	Surface	Partner	Opponent	Score
Loss	1987	Wimbledon	Grass	Nicole Provis	Jo Durie Jeremy Bates	6–7(10–12), 3–6

Close

Singles

Doubles

Mixed Doubles