Kenneth Eric Allaby (born August 7, 1943 on Grand Manan Island, New Brunswick) is a New Brunswick politician.

Allaby, educated in physics at Acadia University, had held a variety of occupations throughout his life. He was an author, painter, curator and teacher.

He first ran for the Legislative Assembly of New Brunswick, as a Liberal in the 1982 election but was defeated. He ran again in 1987 and gained a seat in Frank McKenna's landslide that saw the Liberals capture every seat. He was re-elected in 1991, 1995, 1999 and 2003.

Soft spoken, but known for his keen knowledge of parliamentary procedure, Allaby was a candidate for speaker in 1998 and was named Liberal House Leader following the 1999 election that returned the Liberals to opposition for the first time in 12 years. He currently serves in the opposition shadow cabinet as critic for transportation.