The New Hampshire Interscholastic Athletic Association (NHIAA) is the governing body for sports competitions among all public and some private high schools in New Hampshire. It is a member of the National Federation of State High School Associations.

Classifications

Schools competing under the NHIAA are grouped into four divisions: Schools are reclassified every two years. The classification thresholds are periodically adjusted so as to result in an approximately equal number of teams in each class. Schools may petition the NHIAA to play in a class higher than that in which they would otherwise be placed. For some sports (e.g. football or ice hockey), competition is not organized based on school class, but based on divisions established by the NHIAA committee governing the individual sport. Classifications for the 2022–23 and 2023–24 seasons are as follows:

Division I (formerly Class L)

• Alvirne • Bedford • Concord • Dover • Exeter • Goffstown • Keene • Londonderry • Manchester Central • Manchester Memorial • Merrimack • Nashua North • Nashua South • Pinkerton • Portsmouth • Salem • Spaulding • Timberlane • Windham • Winnacunnet • Bishop Guertin

Division II (formerly Class I)

• Bow • Coe-Brown • ConVal • Hanover • Hollis/Brookline • John Stark • Kennett • Kingswood • Laconia • Lebanon • Manchester West • Merrimack Valley • Milford • Oyster River • Pelham • Pembroke • Plymouth • Sanborn • Souhegan

Division III (formerly Class M)

• Belmont • Berlin • Campbell • Conant • Fall Mountain • Gilford • Hillsboro-Deering • Hopkinton • Inter-Lakes • Kearsarge • Mascoma Valley • Monadnock • Newfound • Newport • Prospect Mountain • Raymond • Somersworth • St. Thomas Aquinas • Stevens • Trinity • White Mountains • Winnisquam

Division IV (formerly Class S)

• Bishop Brady • Canaan • Colebrook • Concord Christian • Derryfield • Epping • Farmington • Franklin • Gorham • Groveton • Hinsdale • Holy Family • Lin-Wood • Lisbon • Littleton • Mascenic • Moultonborough • Mount Royal Academy • Newmarket • Nute • Pittsburg • Pittsfield • Portsmouth Christian • Profile • Sunapee • Wilton-Lyndeboro • Woodsville

Sports

The NHIAA sanctions competitions in the following sports:

Fall season

Winter season

Spring season