Tottenham announced the signing without disclosing a fee. British media said Bissouma was costing an initial 25 million pounds ($30.5 million).
Bissouma has played for Brighton since 2018 after joining from Lille, making 123 appearances in all competitions.
His arrival provides competition in central midfield for Pierre-Emile Hojbjerg, Rodrigo Bentancur and Oliver Skipp.
