McGregor is located just southwest of Waco toward Gatesville on US 84 in McLennan County.
McGregor is part of the Waco, Texas metro area.
It was established in 1882 at the junction of the St. Louis Narrow Gauge and Santa Fe Railroads 14 miles west of Waco. The historic downtown district dates from 1900. McGregor Mirror offices display original printing equipment used in 1883 to publish McGregor Plaindealer.
Industries include the Hercules naval weapons plant producing solid rocket motors and missiles, and A&M beef cattle research station.
The population was 4,289 in 1978 and 4,683 in 1990.