A new cultivar of Dianthus plant named ‘FLORIAGATE’ is characterized inter alia by pronounced spray habit, perennial and profuse bloom, and green foliage. Dianthus ‘FLORIAGATE’ is suitable for use as a flowering plant in pots, containers, window boxes and the garden, but is primarily suited for the production of cut flowers. Dianthus ‘FLORIAGATE’ is not hardy and is grown in a glasshouse. These traits set ‘FLORIAGATE’ apart from all other existing varieties, lines, strains or sports of Dianthus. In particular, Dianthus ‘FLORIAGATE’ has bright purple/violet flowers.