SeaCat can refer to:

• Sea Cat, a surface-to-air missile
• SeaCat, a former Scottish ferry service
• SeaCat Tasmania, former name of the ferry HSC Emeraude France
• Sea Cat, a Dungeons & Dragons monster.
• Ariidae, a family of catfish sometimes called "sea cat" or "sea catfish".
• Black-tailed gull, a family of gulls sometimes called umineko ("sea cat" in Japanese) due to their cat-like calls.
• Umineko When They Cry, a visual novel often nicknamed "seacats" by fans due to the name (which refers to the black-tailed gull).