Lasswade is a parish, which lies in Midlothian Council Area, some 2 miles (4 km) southwest of Bonnyrigg and 3 miles (5 km) northeast of Penicuik in Midlothian.
It is located in the old county of Midlothian, which disappeared following the Local Government (Scotland) Act 1974.
The parish has an area of 40.5 sq. km (15.6 sq. miles). Lasswade has 7 neighbouring parishes; namely Carrington, Cockpen, Dalkeith, Edinburgh, Glencorse, Newbattle and Penicuik. The boundaries of this parish were modified as a consequence of the Local Government (Scotland), 1894.