Lyndon is located at (41.716821, -89.923186).
There were 236 households out of which 27.1% had children under the age of 18 living with them, 57.6% were married couples living together, 8.5% had a female householder with no husband present, and 29.7% were non-families. 24.2% of all households were made up of individuals and 14.0% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.81.
In the village the population was spread out with 21.7% under the age of 18, 7.6% from 18 to 24, 28.4% from 25 to 44, 27.7% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 102.1 males. For every 100 females age 18 and over, there were 96.9 males.
The median income for a household in the village was $37,375, and the median income for a family was $41,528. Males had a median income of $30,469 versus $22,813 for females. The per capita income for the village was $16,870. About 5.6% of families and 6.8% of the population were below the poverty line, including 3.6% of those under age 18 and 10.5% of those age 65 or over.
Lyndon is also known as the "Crow Capital of the World", celebrated in the past with a Crow Festival. The village at one time had an official mascot which was a real life crow, named Rocky the Crow.