Laurence O'Brien (1792 – April 28, 1870) was an Irish-born merchant and politician in Newfoundland.
He represented St. John's in the Newfoundland and Labrador House of Assembly from 1841 to 1850 as a Liberal.
O'Brien owned a wharf, warehouses and a retail store, and was also the owner of several trading ships.
He was first elected to the Newfoundland assembly in an 1840 by-election held after Patrick Morris was named to the colony's Council.
He resigned his seat in the assembly in 1850 after he was named to the Legislative Council.