‘Galaxy’ thornless, semierect blackberry that produces large yields of very firm and excellent-flavored fruit that should be well suited to fresh market production in the early season for a semierect blackberry. ‘Galaxy’ is higher yielding and has larger, better flavored, and/or firmer fruit than current cultivars ripening in this season. Although ‘Galaxy’ is expected to be adapted to areas where other semierect blackberries (e.g., ‘Chester Thornless’, ‘Triple Crown’) can be grown successfully, it should be tested on a moderate scale in colder regions before being widely planted.