天顶是在天球座标系统中位于观测者正上方的点。在地平座标系统中，此点的高度为90度。

• 天顶距
• 大地学
• 大地学历史
• 垂直偏差

Zenith (UK /ˈzɛnɪθ/, US /ˈziːnɪθ/) refers to an imaginary point directly "above" a particular location, on the imaginary celestial sphere. "Above" means in the vertical direction opposite to the apparent gravitational force at that location. The opposite direction, i.e. the direction in which gravity pulls, is toward the nadir. The zenith is the "highest" point on the celestial sphere (meaning it is the farthest up from the gravitational force). Zenith is sometimes used as a given name, most commonly for males. Its meaning, "highest point," evokes success and power.