Tribune is located at 38°28'13N, 101°45'16W (38.470288, -101.754489). According to the United States Census Bureau, the city has a total area of 1.9 km² (0.8 mi²), all land.
As of the census of 2000, there were 835 people, 356 households, and 232 families residing in the city. The population density was 429.9/km² (1,117.0/mi²). There were 425 housing units at an average density of 218.8/km² (568.5/mi²). The racial makeup of the city was 94.37% White, 0.12% African American, 0.36% Native American, 0.12% Asian, 0.24% Pacific Islander, 3.59% from other races, and 1.20% from two or more races. Hispanic or Latino of any race were 6.35% of the population.
There were 356 households out of which 28.9% had children under the age of 18 living with them, 57.9% were married couples living together, 5.1% had a female householder with no husband present, and 34.8% were non-families. 31.7% of all households were made up of individuals and 16.6% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.87.
In the city the population was spread out with 23.6% under the age of 18, 6.1% from 18 to 24, 24.1% from 25 to 44, 22.2% from 45 to 64, and 24.1% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 89.8 males. For every 100 females age 18 and over, there were 82.3 males.
The median income for a household in the city was $32,969, and the median income for a family was $46,563. Males had a median income of $30,132 versus $16,458 for females. The per capita income for the city was $20,020. About 7.0% of families and 9.6% of the population were below the poverty line, including 8.3% of those under age 18 and 9.4% of those age 65 or over.