Alexandria is a city in Monroe Township, Madison County, Indiana, United States. It is about 48 miles (77 km) northeast of Indianapolis. According to the 2020 census, its population was 5,149, nearly unchanged from 2010.

Alexandria was platted in 1836, when it was certain that the Indiana Central Canal would be extended to that point. It was incorporated as a town in 1898.

In 1898, Indiana's first Interurban railway line began operating between Alexandria and Anderson.

Alexandria is located in northern Madison County. Indiana State Road 9 passes through the east side of the city, leading south 11 miles (18 km) to Anderson, the county seat, and north 21 miles (34 km) to Marion. State Road 28 crosses the northern tip of Alexandria, leading west 9 miles (14 km) to Elwood and east 23 miles (37 km) to Albany.

According to the U.S. Census Bureau, Alexandria has a total area of 3.0 square miles (7.8 km²), all land. Pipe Creek crosses the city south of its center, flowing southwest to join the White River at Perkinsville.

Alexandria is part of the Indianapolis–Carmel–Anderson metropolitan statistical area.

As of the 2020 census, Alexandria had a population of 5,149. The median age was 38.4 years. 24.8% of residents were under the age of 18 and 16.6% of residents were 65 years of age or older. For every 100 females there were 95.3 males, and for every 100 females age 18 and over there were 87.8 males age 18 and over.

99.2% of residents lived in urban areas, while 0.8% lived in rural areas.