[12][13] At the age of three Cummins lost the top of his middle finger on his dominant right hand when his sister accidentally slammed a door on it.

[16] Cummins was granted a Cricket Australia contract in June 2011[19] and in October 2011, he played two Twenty20 International (T20I) and three One Day International (ODI) matches for Australia against South Africa, claiming ten wickets and subsequently being selected in the Australian Test squad to play in South Africa.

Cummins was selected in Australia's provisional team for the ICC Under-19 World Cup to be held in Queensland in August 2012.

[16] Cummins returned for Australia A in August 2013, but a recurrence of the stress fracture in his back caused him to miss most of the 2013–14 summer.

[16] After prioritising white ball cricket during 2014, Cummins was selected in the Australian squad for their successful 2015 World Cup campaign, playing in four matches.

Cummins was a late call-up for 2015 Ashes squad after the retirement of Ryan Harris, but was not selected for a test during the series.

During the ODI leg of the tour, Cummins' stress fracture resurfaced and he was ruled out of the entire home summer for the fourth time in five years.

Cummins made his return to domestic cricket in 2016, becoming a key member of the NSW one-day squad and the Sydney Thunder, as he remained fit and played 25 matches in just over 4 months.

Cummins had suffered an injury after the five-match Border-Gavaskar Trophy against India and was not a part of the Australian side touring Sri Lanka for two Test matches.

[27] Despite NSW medical staff recommending a slow and managed return to red ball cricket, Mitchell Starc was ruled out of the ongoing Border–Gavaskar Trophy and Cummins was selected as his replacement for the third Test.

[28] In this series, he solidified his place as one of Australia's most reliable and consistent bowlers, playing in all four matches and claiming 22 wickets.

Cummins was awarded the Allan Border Medal in February 2019 as the most outstanding Australian cricketer over the previous 12 months.

In early 2019 Cummins became the world's number 1 ranked Test bowler, the first Australian since Glenn McGrath to achieve this.

[35] In April, he was named in Australia's squad for the 2019 Cricket World Cup held in England,[36][37] and during the tournament played in his 50th ODI.

[46] During the 2020–21 Border–Gavaskar Trophy Cummins claimed a series-leading 21 wickets at an average of 20.04, and was named player of the series despite Australia's 2–1 loss.

On 26 November 2021 Cummins was announced as the 47th captain of the Australian Test cricket team following the resignation of Tim Paine.

Cummins had to fly back to Australia due to his mother's illness, with Steve Smith taking over as captain for the remaining two matches and the three-match ODI series.

Cummins led Australia to victory in ICC World Test Championship Final 2023 against India, 7–11 June 2023.

He was involved in the record partnership of 202 from 170 balls for 9th wicket with Glenn Maxwell in the eighth league match against Afghanistan.

[57] He picked up 2 crucial wickets of Virat Kohli and Shreyas Iyer in the final, conceding only 34 runs off his 10 overs.

[67] Cummins opted out of IPL 2023, stating that he wanted to focus on his commitments with the national team, including the Ashes series and the ODI World Cup.

[68] Cummins appeared in the 2024 IPL auction, and was bought by the Sunrisers Hyderabad for ₹20.5 crore (A$3.8 million), making him the second-most-expensive player in IPL history after his teammate Mitchell Starc who was bought by the Kolkata Knight Riders for ₹24.75 crore (A$4.6 million) in the same auction.

[70] Cummins attended the University of Technology, Sydney under its Elite Athlete Program,[75] graduating in 2017 with a Bachelor of Business.