Alexander Isak (আলেকসান্দার ইসাক) is a Swedish professional footballer who plays as a striker for Premier League club Newcastle United and the Sweden national team.

Born and raised in Solna, Sweden, Isak started his professional career with boyhood club AIK in 2016 and then represented Borussia Dortmund and Willem II before signing with Real Sociedad in 2019. In 2022, he signed with Newcastle United for a club record fee.

A full Swedish international since 2017, Isak has won over 50 caps for his national team, and represented the side at UEFA Euro 2020. He is the youngest-ever goalscorer for both AIK and the Swedish national team.

Isak was born to Eritrean parents on 21 September 1999 and raised in Solna Municipality, in central Stockholm County. He started playing for the youth team of one of the largest clubs in the area, the Allsvenskan team he supports, AIK, at age six.

Isak played for youth Swedish national teams in the U-16 to U-21 categories. He was called up to the Sweden national team for the friendly matches against Ivory Coast on 8 January 2017 and Slovakia on 12 January. He made his debut against the Ivory Coast, coming on for Per Frick in the 62nd minute of a 1–2 loss. He started the second game against Slovakia, scoring the first goal in a 6–0 win in the 19th minute, becoming the youngest goalscorer ever in the history of the Sweden national team.

On 23 March 2019, Isak made his first competitive appearance for Sweden, when he replaced Robin Quaison in the 88th minute in a UEFA Euro 2020 qualifying game against Romania, which Sweden won 2–1.

Isak has been described as a "true modern striker", offering an aerial presence with his 6'4" frame while possessing notable pace and skills with the ball at his feet, allowing him to manoeuvre through tight spaces and outsmart defenders. Isak's composure in finishing goalscoring opportunities with both feet, and his link up play and passing abilities have also been noted, allowing teammates to join the attack. Isak showcases intelligent positioning and movement in the attacking third of the pitch, ensuring difficulty for him to be marked by opposition defenders, opening up spaces for himself and teammates to exploit in running in behind the defensive line. Out of possession, Isak's workrate and defensive positioning have also been highlighted as key features of his all-round game. Isak has been used as a solo striker, a left winger and in a two-man setup, using his strength to hold up the ball in the former role, while using his speed to exploit gaps in the opposition defence in the latter roles.