Walter G. McGahan, a former Republican State Senator and City Councilman from Queens, died Saturday at his home in Bayside, Queens.

He was 75 years old.

Mr. McGahan, a retired lawyer who remained active in Republican party politics, served in the City Council from 1947 to 1955 and was then elected to successive terms in the State Senate. He also served in various state posts, including Deputy Motor Vehicle Commissioner and Deputy State Superintendent of Insurance.

He was a graduate of the Fordham University School of Law and a commodore of the Bayside Yacht Club. He is survived by his wife, Edna, and a daughter, Jane.