Though his birth was not registered until 1918, Frederick Kenneth McTaggart (known as Ken) was born on 30 November 1917 at Elsternwick, to Victorian Railways industrial chemist Cyril (1881 – 1966), and teacher Hilda Theresa McTaggart (née Daniel, 1882 – 1966), and his sole sibling was an older sister, Jean.
Due to childhood illness his primary education started late; aged eight he entered Grade 4 at Ormond State School, then he was educated from age 13 at Melbourne Boys High School 1931–1936. He joined a school debating team, and the orchestra, of which he was leader in 1934, and was elected a prefect in 1935. He was a ham radio enthusiast, and in his 3rd year at the school was involved in the Wireless Club, of which he became vice-president, and built his own set, the MHS Twin, when in 1934 he was issued an Amateur Radio Licence,. It was an interest that he continued into adulthood and one he maintained throughout his life.
Aged 18 he commenced a Bachelor of Science in Chemistry at Melbourne University and in April 1939 was conferred Bachelor of Science in Wilson Hall, when he had already commenced a Master of Science with John Stuart Anderson working on the separation of hydrogen fluoride and zirconium for which he received 1st Class Honours in 1940. A Doctor of Science was conferred on him in 1965 by Melbourne University in recognition of his work on the chemistry of titanium and zirconium, and on reactions in low pressure discharges.