The 27-year-old forward was a free agent, having recently left Hull City when his contract expired.
He spent four years with the Tigers, making 118 appearances for them and scoring 15 goals.
Aluko, who can play on the wing or through the middle, represented England at youth level and has since won seven caps for Nigeria.
He began his career at Birmingham City and played in Scotland for Aberdeen and then Rangers before joining Hull.
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Fulham have signed Sone Aluko on a two-year contract with the option of a further year.