Watson moved north from the Leicester Tigers Academy for a centrally held Scotland 7s contract in the summer of 2011 before being approached to join the club’s elite development programme following a string of impressive showings in the back-row.

Watson made his first appearance for the club against Cardiff Blues in 2011, but it wasn’t until 2013 that the back-row grabbed his first try for the club. It happened to be on his first start for the capital side against Ospreys.

The back-row nailed down a starting spot at the beginning of the 2014/15 season as Edinburgh stared the year with an impressive away victory over Munster, and it wasn’t long until Watson was playing himself into international contention.

The back-row was rewarded with a senior international debut in the 2015 RBS 6 Nations Championship, against Italy at BT Murrayfield.

It was just over a year until Watson got another chance at senior international honours, an opportunity he grabbed with both hands, bringing his relentless club form to the national team set-up and subsequently earning the starting seven jersey in all but one of eight tests in an impressive 2016/17 season.

The icing on the cake came in the second summer test when his lung-busting support line saw him cross the whitewash for his second Scotland try against the Wallabies, in the national team’s historic win in Sydney.

Hamish went on to start in all Autumn Tests that year, as well as Scotland’s five tests at the 2018 NatWest 6 Nations.

Watson made his 100th appearance in the 1872 Cup match-up against Glasgow Warriors in April 2019, while he signed a two-year extension ahead of the 2019/20 campaign.

Having suffered an injury at 2019 Rugby World Cup, Watson worked tirelessly to return to action and made his comeback in a famous away victory over Munster in November of the same season.

The back-row’s every-industrious form continued into 2020-21 as he picked up Player of the Match in the club’s Heineken Champions Cup victory away to Sale Sharks in December 2020.

Watson agreed terms to a new long-term deal with the club in January 2021 and joined back-row teammates Bill Mata and Jamie Ritchie in committing his future to Edinburgh Rugby.

Club legend Watson picked up his 150th appearance for the club in an away win against Zebre Parma in February 2023, becoming the most-capped back row in Edinburgh Rugby’s history.