The summer transfer window opens on June 15 and closes at 11pm UK time on September 1. Clubs across the Scottish Premiership have begun reshaping squads ahead of the 2026 World Cup. Aberdeen signed free agents Lewis Mayo and Brad Lyons from Kilmarnock, while Alexander Briedl joined from Blau‑Weiss Linz.

Aberdeen also lost several players whose contracts expired: Graeme Shinnie departed for Inverness Caledonian Thistle, and Ryan Duncan, Vicente Besuijen, Elvis Bwomono, Tom McIntyre, and others exited the club. Dundee United welcomed Jack Walton from Preston North End but saw Craig Sibbald, Ryan Strain, and Johnny Russell all leave on free transfers.

Falkirk secured Craig Sibbald from Dundee United and added Jack McMillan from Exeter City and Scott Tanser from St Mirren, all on free deals. Departures included Gary Oliver, Sean Mackie, Brian Graham, and Jamie Sneddon, all whose contracts ended.

Celtic announced the retirement of goalkeeper Kasper Schmeichel, while Dundee and Dundee United both saw multiple contract expirations and loan terminations. These movements set the stage for a competitive pre‑World Cup season as clubs aim to strengthen their squads for 2026.