| Constituents of the London & South Western Railway |
| Bodmin & Wadebridge Railway 1832-1886 | London & Southampton Railway 1834-1839 | North Devon Railway & Dock Co 1851-1865 | Guildford Junction Railway 1844-1845 |
| Richmond Railway 1845-1847 | Southampton & Dorchester Railway 1845-1848 | Exeter & Crediton Railway 1845-1879 | Basingstoke & Salisbury Railway 1846-1849 |
| Windsor, Staines & South Western Railway 1847-1848 | London Necropolis Railway 1852 | Portsmouth Railway 1853-1861 | Bideford Extension Railway 1853-1865 |
| Staines, Wokingham & Woking Railway 1854-1878 | Salisbury & Yeovil Railway 1854-1878 | Stokes Bay Railway 1855-1875 | Exeter & Exmouth Railway 1855-1866 |
| Lymington Railway 1856-1879 | Wimbledon & Dorking Railway 1857-1862 | Epsom & Leatherhead Railway 1856-1864 (Joint with LBSCR) | Andover & Redbridge Railway 1858-1864 |
| Ringwood, Christchurch & Bournemouth Railway 1859-1874 | Chard Railway 1860-1863 | Petersfield Railway 1860-1863 | Mid Hants (Alton Lines) Railway 1865-1884 |
| Salisbury & Dorset Junction Railway 1861-1883 | Southampton & Netley Railway 1861-1864 | Bishop's Waltham Railway 1862-1863 | Thames Valley Railway 1862-1865 |
| Devon & Cornwall Railway 1870-1872 | Plymouth, Devonport & SW Junction Railway 1883-1922 | Tamar, Kit Hill & Callington Railway 1862-1869 | Callington & Calstock Railway 1869-1871 |
| Seaton & Beer Railway 1863-1888 | Poole & Bournemouth Railway 1865-1882 | Barnstaple & Ilfracombe Railway 1870-1874 | Southsea Railway 1880-1883 (Joint with LBSCR) |
| Waterloo & City Railway 1893-1907 | Budleigh Salterton Railway 1894-1911 | Basingstoke & Alton Light Railway 1897 | Axminster & Lyme Regis Light Railway 1899-1907 |
| West London Extension Railway (Joint with GWR, LNWR & LBSCR) | Somerset & Dorset Railway 1862 - Joint Lease L&SWR and Midland from 1875 | Tooting, Merton & Wimbledon Railway 1864-1878 (Joint with LB&SCR) | Portsmouth & Southsea Joint Railway 1848 with LB&SCR |
| The Bridgwater Railway of 1882 remained nominally independent untill aquired by the L&SWR at grouping in 1923. | | | |
