Herbert Arthur Sinnott (January 7, 1871 – after 1923) was a Canadian educator, lawyer and municipal politician who served as the 18th mayor of Calgary, Alberta from 1913 to 1915.

[3] In January 1923, Sinnott pleaded guilty in a court to "misappropriating clients' trust funds" during his work as a lawyer in Calgary.

[5] During his trial, Sinnott admitted his guilt and was sentenced to seven years to be served in a Prince Albert, Saskatchewan jail.

[5] The magistrate also expressed that the punishment was decided to set a precedent and to "deter others from doing the same thing", along with restating that though it was hard to see "a citizen of Mr. Sinnott's calibre" take the sentence, it was a necessary justice.

[1] Sinnott was widely regarded for his work in the educational field, with a 1912 biography beginning with "The educational annals of the Northwest present few names which shine with a brighter luster of good deeds done than the one which forms [this paragraph]".