The 27-year-old forward joins the Maroon after top striker Osman Sow was sold for a fee in excess of £1m to Chinese club Henan Jianye.
“I’m really happy to have signed, it’s been a long day but this has been worth waiting for,” Dauda told club website.
“I’ve had a great welcome here. I spoke with Robbie on the phone and he told me he has followed me for quite a while now, and as a player it is a dream to hear a coach say that.
“Now I have to go on the pitch and show him he made the right decision. I’m really looking forward to meeting my teammates and learning the team’s style of play,” he concluded.
Dauda joins compatriot Juwon Oshaniwa in Robbie Neilson’s fold and he is expected to feature for Hearts in Sunday’s Scottish Cup fifth round tie against Hibs at Tynecastle.
He will compete for a place up front with Gavin Reilly, Juanma Delgado and Dario Zanatta.