Hibernian Raised in
Dalkeith in Midlothian, He played youth football for Edinburgh club Edina Hibs and then
Aberdeen before returning to Edinburgh to sign for his boyhood club. After establishing himself in the Hibernian
youth system, he was loaned to
Edinburgh City for the
2016–17 season and scored goals that secured wins against
Annan Athletic (Edinburgh City's first in the
SPFL) and
Arbroath. Although becoming a regular in the senior squad during that season (30 times an unused substitute in addition to six
Scottish Premiership matches in which he did feature), Porteous also continued to appear for the club's
Under-20s, whose campaign ended with a 'double' of
SPFL Development League and
Scottish Youth Cup. During October 2018, Porteous signed a new contract with Hibernian, which was due to run until the summer of 2023. He suffered a knee injury in January 2019 that required surgery, which prevented him from playing for the rest of the 2018–19 season. On 20 December 2019, Porteous was shown a straight
red card for a dangerous tackle on Rangers player
Borna Barišić, with the incident provoking an angry confrontation between both coaching teams. Porteous suffered a serious knee injury during a Scottish Cup match at
Dundee United in January 2020. He returned from the injury ahead of the 2020–21 season, in which Hibs finished in third place and reached the
2021 Scottish Cup Final. Hibs turned down a bid of around £1 million from
Millwall for Porteous in January 2021. His 2021–22 season was disrupted by suspensions, as he was sent off twice and also banned retrospectively once. In the same week as his widely praised debut for the Scotland national team, Porteous scored his first goal of the 2022–23 season with the opener in a 2–0 victory at
Ross County on 1 October 2022. Hibs announced in November that Porteous had turned down their offer of a new contract. In January 2023, Porteous was subject of interest from
Serie A side
Udinese and
EFL Championship side
Blackburn Rovers. Hibs accepted an offer from
Watford, another Championship club, of around £450,000.
Watford On 27 January 2023, Porteous signed a contract with
Watford which was due to run until the end of the 2026–27 season. He scored a goal during his first appearance for Watford, a 2–2 draw at
Reading on 4 February.
Preston North End (loan) On 3 February 2025, Porteous joined
EFL Championship side
Preston North End on loan until the end of the season.
Los Angeles FC On 4 August 2025, Porteous signed for
Major League Soccer side
Los Angeles FC until the end of the 2028 season, with an option to extend until 2029. Los Angeles FC also had to pay
Toronto FC $100,000 in Discovery Priority rights to complete the signing. ==International career==