As of the census of 2000, there were 15,814 people, 6,485 households, and 4,461 families residing in the CDP. The population density was 2,142.1 people per square mile (827.3/km²). There were 6,614 housing units at an average density of 895.9/sq mi (346.0/km²). The racial makeup of the CDP was 90.10% White, 3.22% African American, 0.15% Native American, 5.27% Asian, 0.01% Pacific Islander, 0.24% from other races, and 1.01% from two or more races. Hispanic or Latino of any race were 1.22% of the population.
There were 6,485 households out of which 24.7% had children under the age of 18 living with them, 59.4% were married couples living together, 7.1% had a female householder with no husband present, and 31.2% were non-families. 26.3% of all households were made up of individuals and 14.7% had someone living alone who was 65 years of age or older. The average household size was 2.36 and the average family size was 2.86.
In the CDP the population was spread out with 19.7% under the age of 18, 4.9% from 18 to 24, 24.6% from 25 to 44, 27.0% from 45 to 64, and 23.7% who were 65 years of age or older. The median age was 46 years. For every 100 females there were 90.1 males. For every 100 females age 18 and over, there were 87.5 males.
The median income for a household in the CDP was $61,573, and the median income for a family was $74,464. Males had a median income of $52,401 versus $35,132 for females. The per capita income for the CDP was $32,369. About 0.8% of families and 3.6% of the population were below the poverty line, including 0.6% of those under age 18 and 5.1% of those age 65 or over.
Maryland Route 45, better known as York Road, is the main corridor running through the Lutherville and Timonium areas. Most of the area's commercial development is located either on or near York Road.
Maryland Route 131, better known as Seminary Avenue, is a cross-county route that runs between the area near Greenspring Station and Providence Road, passing through historic Lutherville. The road is lined mostly with residential development and crosses over Interstate 83.
Ridgely Road is a 1.6-mile (3 km) thoroughfare that is mostly residential, except for the portion west of York Road ending at the Lutherville Light Rail Stop. This two-block section is lined with large shopping centers and a Maryland Transit Administration (MTA) public transportation hub for the area.
Timonium Road is an approximately 4-mile (6 km) road that runs west-east across the Timonium area, mostly through residential neighborhoods. A small portion of the road between York Road and an interchange with I-83 is commercially developed, and includes an entrance to the parking for the Maryland State Fairgrounds. Some ramps in the interchange can be found on the intersecting Deereco Road.
Deereco Road runs parallel to I-83, and is lined mostly with businesses and warehouses. The Timonium Light Rail Stop is also located on Deereco Road.
The Md. Transit Administration (MTA)'s light rail line has three stops in the Lutherville-Timonium area. In addition, bus routes 8 and 9 provide regular service along the York Road corridor, meeting at the Lutherville Light Rail Stop. There is also a limited amount of bus service on route 12 to Stella Maris Hospice.
The MTA light rail line uses the right-of-way of the old Northern Central Railway. During the Civil War, President Abraham Lincoln travelled through Lutherville on this railroad en route to Gettysburg, Pennsylvania to deliver the Gettysburg Address on November 19, 1863. Less than two years later, on April 21, 1865, Lincoln's funeral train also passed through Lutherville on its way from Washington, D.C. to his final resting place at Springfield, Illinois.