Lyne is a small parish, which lies in the Scottish Borders Council Area, some 4 miles (6 km) west of Peebles in the Scottish Borders and 12 miles (19 km) south of Penicuik in Midlothian.
It is located in the old county of Peeblesshire, which disappeared following the Local Government (Scotland) Act 1974.
The parish has an area of 11.3 sq. km (4.3 sq. miles). Lyne has 4 neighbouring parishes; namely Eddleston, Newlands, Peebles and Stobo. The boundaries of this parish were modified among significant changes recommended by the Boundary Commissioners after the Local Government (Scotland) Act 1889.