Cassini may refer to:

• Cassini (surname)
• Oleg Cassini (1913–2006), American fashion designer

Cassini family:

• Giovanni Domenico Cassini (1625–1712), Italian mathematician, astronomer, engineer, and astrologer
• Jacques Cassini (1677–1756), French astronomer, son of Giovanni Domenico Cassini
• César-François Cassini de Thury (1714–1784), French astronomer and cartographer, son of Jacques Cassini
• Jean-Dominique, comte de Cassini (1748–1845), French astronomer, son of César-François Cassini de Thury
• Alexandre Henri Gabriel de Cassini (1781–1832), French botanist and naturalist, son of Jean-Dominique de Cassini

• Cassini's laws on the motion of the Moon
• Cassini Division, a gap in the rings of Saturn
• Cassini–Huygens, the space mission to examine Saturn and its moons, of which the Cassini orbiter was a part
• Cassini (Martian crater)
• Cassini (lunar crater)
• 24101 Cassini, an asteroid
• 24102 Jacquescassini, another asteroid
• Cassini Regio, the dark region of the moon Iapetus

• Cassini, South Australia
• Cassini oval, a mathematical curve described by Giovanni Cassini
• Cassini projection, in map making
• Cassini Glacier, in Antarctica
• Cassini periodical cicadas, two species of insect
• French cruiser Cassini, French Navy cruiser

• Casini, a surname