I class may refer to:
*
''Acheron''-class destroyer, a class of destroyers that served in World War I
*
I-class destroyer, a class of destroyers of the 1930s
*
I-class ferry, a class of ferries operated by BC Ferries
*
''Istanbul''-class frigate, a late 2010s class of indigenous Turkish frigates
See also
*
Class I (disambiguation) Class I may refer to:
* Class I antiarrhythmic
* Class I electrical appliance, a device constructed according to electrical grounding specifications in the IEC 60536-2 standard
* Class I bacteriocin, a type of toxin produced by some bacteria
*Clas ...
{{disambiguation