A hypothesis is a proposed explanation for a phenomenon.
Hypothesis may also refer to:
Hypothesis (album), music by Vangelis Hypothesis (drama), in ancient usage, a summary of the plot of a classical drama Hypothesis of a theorem, in mathematics Hypothes.is, a website annotation software Hypothesis Z, the first Romanian war plan for World War I
Hypothetical may also refer to: Hypothetical mood, a grammatical mood found in some languages Geoffrey Robertson's Hypotheticals, an Australian TV panel show Hypothetical (album), a 2001 progressive metal album Hypothetical (TV series), a comedy TV show