Tidal wave may refer to:

Seas and oceans
A tidal bore, which is a large movement of water formed by the funnelling of the incoming tide into a river or narrow bay
A storm surge, or tidal surge, which can cause waves that breach flood defences
A tsunami, a series of water waves in a body of water caused by the displacement of a large volume of water, although this usage of "tidal wave" is a misnomer and is disfavored by the scientific community.
"Tidal Wave", a song by Thee Oh Sees
"Tidal Wave", a song by The Upsetters
"Tidal Wave", a song by Portugal. The Man
"Tidal Wave", a song by S*M*A*S*H
"Tidal Waves", a 2015 song by All Time Low from Future Hearts
"Tidal Wave", a 1974 song by The Ozark Mountain Daredevils from Itll Shine When It Shines
"Tidal Wave", a song by Chase Atlantic, 2018

See also
A rogue wave of up to 100 feet high, often in the middle of the ocean and against prevailing current and wave direction