The Ottawa Senators, officially the Ottawa Senators Hockey Club and colloquially known as the Sens, are a professional ice hockey team based in Ottawa.

The 100 seats in the United States Senate are divided into three classes for the purpose of determining which seats will be up for election in any two-year cycle, with only one class being up for election at a time.

a Minor League Baseball team who play in the Eastern League, and are the Double-A affiliate of the Washington Nationals.

a parliamentary group in the Senate of Canada.

a parliamentary group of senators in the Senate of Canada founded on November 4, 2019, by eight senators from the Independent Senators Group, two from the Conservative Party of Canada's Senate caucus, and one non-affiliated senator.

a professional ice hockey team in the American Hockey League that began play in the 2017–18 season as the top minor league affiliate of the National Hockey League's Ottawa Senators.

members of the Italian Senate who are either appointed, limited in number up to five, by the Italian president "for outstanding patriotic merits in the social, scientific, artistic or literary field" or are former presidents and thus senators for life ex officio.