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. Sinnott was born in Kings County, New Brunswick on January 7, 1871 to David S., a farmer, and Frances (née Taylor) Sinnott. After attending schools in Sussex, New Brunswick, Sinnott graduated from Mount Allison University with a Bachelor of Arts and started his teaching career in Gagetown as principal of a grammar school. He later taught high school in Moncton, New Brunswick before moving west to Alberta in 1900. In 1903, he became a high school principal in Calgary, the first ever to the city. He began a career in law in 1908, articling under Thomas M. Tweedie. In 1911, he was called to the bar. Around this time,