He was also organising secretary of the New South Wales Temperance Alliance, and held other prominent positions in railway unions.

[2] Catts's first attempt to enter politics was unsuccessful, running in the 1904 state election as the Labor candidate for Granville.

He became the youngest member of the Australian House of Representatives in 1906 when he was elected to the seat of Cook at the age of 28, and became associated with King O'Malley and Billy Hughes.

In his retirement, Catts became secretary and treasurer of the New South Wales branch of the British Astronomical Association, devoting more time to his hobby of astronomy.

[2] In 1919, his first wife petitioned for divorce on the grounds of adultery, alleging her husband had engaged in an extramarital affair with Dorothy Purcell that resulted in the birth of a child.

[6] His first wife was awarded alimony, with the presiding judge finding that Catts had illegally concealed assets in order to reduce the settlement.

After his death, Dorothy Catts published biographies both of her husband and of his political ally King O'Malley.