The 56 weapons include shotguns, rifles, handguns and pistols along with rounds of ammunition. Several replica and BB guns were also received.
The amnesty was prompted by a change in the law in July, when the maximum penalty for possession increased from 10 years' imprisonment to life.
The force said: "Our streets are safer now as a result of this initiative."
More than 50 firearms have been handed in to Humberside Police during a two-week gun amnesty.