Possibly the most famous class of Federation vessel ever, the distinctive and readily recognisable Constitution class came to include multiple sub-classes incorporating variations on the original design.
- Constitution class, the original design first launched in 2245 and collective term for all design variants.
- Bonhomme Richard sub-class, the second batch first launched in 2253 with various minor improvements.
- Achernar sub-class, the third batch first launched in 2261 with various minor improvements.
- Indefatigable sub-class, the fourth batch first launched in 2267 with additional weaponry and tactical systems.
- Enterprise sub-class, a radical new "high-end" re-design of the basic Constitution hull form to accept linear warp drive and numerous "New Technology" advances in ship design and systems, first launched in 2272 and consisting entirely of converted vessels of previous classes.
- Constitution-II sub-class, a less extensive "middle ground" re-design of the basic Constitution hull form to accept linear warp drive, first launched in 2273 and consisting entirely of converted vessels of previous classes.
- Endeavour sub-class, a minor "low-end" upgrading of the basic Constitution hull form to incorporate some" New Technology" elements, first launched in 2278 and consisting entirely of converted vessels of previous classes.
- Tikopai sub-class, a chiefly exploratory variant blending elements of the Enterprise and Constitution-II sub-classes, first launched in 2280 and consisting entirely of new-build vessels.
- Levant sub-class, alternately known as the Enterprise-II or Constitution-III sub-classes, an upgrading of the Enterprise sub-class consisting of both converted vessels of previous classes and new-build vessels.