Early and personal life

Weir was born and raised in Amanzimtoti, South Africa. He studied at Westville Boys' High School and the University of Cape Town. A South African with Italian heritage, Weir said it was his having listened to his grandfather Mario's sporting tales of his time in Italy,^[3] that made him decide to represent Italy after completing his degree in finance and accounting. His grandfather had been a keen sportsman.^[6]

2021

He produced a personal best of 21.11 m in February 2021 – 1 cm over the qualifying mark to book his spot for the trip to Japan and the delayed 2020 Tokyo Olympics.^[7][1]

In May 2021, at the Diamond League Meeting in Doha he finished 5th.^[8]

In the delayed 2020 Olympic Games held in Tokyo in 2021, he placed 5th overall in the Qualification round on August 3, 2021, after finishing 3rd in group B with a personal best toss of 21.25. Two days later, he placed again 5th in the Olympic final, with a new PB of 21.41.

He produced another new personal best on September 5, 2021, at the Meeting Città di Padova in Italy with a mark of 21.63 m,^[9] improving his personal best from Tokyo 2020 by 22 centimeters,^[10] improved again in Caorle on 19 September, to bring it to 21.66 m.

He improved his personal record on March 13, 2022 at the 2022 European Throwing Cup, in Leiria with a mark of 21.99 m, winning the competition.

2023: European Indoor champion

Weir broke the Italian indoor national record on the way to throwing 22.06 and winning gold at the 2023 European Athletics Indoor Championships in Istanbul, on March 3, 2023.^[11]

He was selected for the shot put competition at the 2023 World Athletics Championships in Budapest, where he qualified for the final.^[12]

He improved his personal record on September 3, 2023 at the Meeting Città di Padova with a mark of 22.44 m.^[13]

2024

In February 2024, he won the Italian indoor national title with a throw of 21.69m.^[14] He competed in the shot put at the 2024 Summer Olympics in Paris in August 2024, placing eleventh in the final.^[15]

2025

On 4 February 2025, he took an early World lead with a distance of 21.39 metres to win the Czech Indoor Gala in Ostrava.^[16] He was runner-up to compatriot Leonardo Fabbri, who took over the world lead, at the Copernicus Cup on 16 February 2025.^[17] He was selected for the 2025 European Athletics Indoor Championships in Appeldoorn.^[18] He was selected for the 2025 World Athletics Indoor Championships in Nanjing in March 2025, where he placed eighth overall.^[19][20] He was runner-up at the 2025 Diamond League event at the 2025 Golden Gala in Rome on 6 June 2025.^[21] He competed at the 2025 World Championships in Tokyo, Japan.^[22]