According to the 2001 census, Waltham had a population of 6,425. It is five miles southwest of Grimsby and is close to the villages of Scartho, Brigsley, Barnoldby-le-Beck, and Bradley. A few miles to the northeast, there is a similarly named village, New Waltham.
Waltham's attractions include Waltham Windmill, which is used as the symbol for the village's Infant and Junior schools. The windmill was originally built in 1666, but was blown down several times. It was last re-built in 1873. The village is also home to two pubs, namely The Kings Head and the Tilted Barrel, as well as to the Waltham Tea Gardens. A branch of the British Legion is also based in Waltham.
Nearby is the former World War II bomber airfield RAF Grimsby, which was originally the Grimsby Municipal Airport. After the start of WWII the airport was re-constructed by the Air Ministry and became home to 142 Squadron then later on to 100 Squadron and 550 Squadron before closing in 1945. A museum at the Waltham Windmill houses a section dedicated to RAF Grimsby.