The Sri Lankan rupee (Sinhala: රුපියල්, Tamil: ரூபாய்; symbol: ₨ in English, රු in Sinhala, ௹ in Tamil; ISO code: LKR), known until 1972 as the Ceylon rupee, is the currency of Sri Lanka. It is subdivided into 100 cents (Sinhala: සත, Tamil: சதம்), but cents are rarely seen in circulation due to their low value. It is issued by the Central Bank of Sri Lanka. The abbreviation Re (singular) and Rs (plural) is generally used, the World Bank suggests SL Rs as a fully disambiguating abbreviation for distinction from other currencies named "rupee".

Sterling became Ceylon's official currency in 1825, replacing the Ceylonese rixdollar at a rate of £1 = 13+1⁄3 rixdollars, and British silver coins were made legal tender. Treasury notes denominated in sterling were issued in 1827, replacing the earlier rixdollar notes. Rixdollar notes not presented for exchange were demonetized in June 1831.

The Indian rupee was made Ceylon's standard coin on 26 September 1836, and Ceylon reverted to the Indian currency area. Sterling-denominated treasury notes continued to circulate after 1836, along with the rupee. The legal currency remained British silver and accounts were kept in pounds, shillings and pence. However, payments were made in rupees and annas at the "fictitious par" (fixed accounting rate) of two shillings per rupee (i.e. £1 = Rs. 10/-).

The Bank of Ceylon was the first private bank to issue banknotes on the island (1844) and Treasury notes were withdrawn in 1856.

The Indian rupee was formally established as the unlimited legal tender 18 June 1869. The rupee was decimalized 23 August 1871. Thus, the rupee of 100 cents became Ceylon's money of account and sole legal tender effective 1 January 1872, replacing sterling at a rate of Re. 1/- equalling two shillings and three pence sterling.

Following the Ceylon banking and monetary crisis of 1884, in which the largest exchange bank in the island, The Orient Bank experienced an acute liquidity shortage, resulting in a run on the other two exchange banks, Chartered Mercantile Bank and the Bank of Madras. The Government of Ceylon, stepped in an enacted the Paper Currency Ordinance of 1884 which was based on a similar Ordinance in Mauritius in 1876. The Paper Currency Ordinance, established a currency board, the Board of Commissioners of Currency of Ceylon was established consisting of the Colonial Secretary of Ceylon, the Treasurer of Ceylon, and the Auditor-General of Ceylon. This Ordinance linked the Ceylon currency notes and the Indian silver rupees being mutually convertible at the office of the Currency Commissioners at a nominal par without any commission of one Ceylon rupee note to one Indian rupee coin.

By April 2022, political upheaval in Sri Lanka made the Sri Lankan rupee the world's "worst performing currency," according to the Financial Times. The currency's exchange rate had plummeted to over Rs. 350/- = US$1 as of 29 April 2022^[update].

In 1872, copper 1⁄4c, 1⁄2c, 1c and 5c coins dated 1870 were introduced, followed in 1892 by silver 10c, 25c and 50c. Production of the 1⁄4c ceased in 1904. The large, copper 5c coin was replaced in 1909 by a much smaller cupro-nickel coin which was square with rounded corners. In 1919, the fineness of silver used was reduced from .800 to .550.