Ides may refer to:

• A day in the Roman calendar, that marked the approximate middle of the month.
• An Irish saint, better known as Ita or Ida;
• A Plastics Materials Information Management Company: IDES Inc.;
• A brand of malt liquor called "St. Ides."
• The Irish saint and the malt liquor combined to inspire the song St. Ides Heaven by Elliot Smith, released on his eponymous album in 1995;
• The malt liquor also inspired a song St. Ides by the Wu-Tang Clan;
• IDES = a manner of vociferous attack used in Usenet discussion groups. The acronym sums up the technique generally: "intimidate, demoralize, emasculate, subjugate". It specifically involves immediate, wild, at times nonsensical, hateful, insulting personal attacks, without termination. At times attacks are performed by marketing personnel and/or Third World workers; often in connection with FUD. IDES is about using anarchy against those who might gain from anarchism.