SMBC Nikko Securities Inc. (SMBC日興証券株式会社) is a securities firm in Japan which engages in the operation of large-scale comprehensive securities broking and trading services. The company was founded in 2009 and is headquartered in Tokyo, Japan. It is a wholly owned subsidiary of the Sumitomo Mitsui Financial Group. It is the third largest securities brokerage firm in Japan.

The origins of SMBC Nikko Securities can be traced back to a company named Kawashimaya Shoten (川島屋商店) which was formed in July 1918 by Genichi Toyama. It was formed to buy and sell stocks and bonds.

In 1920, the firm was created out of the securities department of the Industrial Bank of Japan and incorporated as a stock company. In 1939, Kawashimaya Shoten spun off its securities division forming Kawashimaya Securities. In 1943, Kawashimaya Securities absorbed Kawashimaya Shoten. In 1944, Kawashimaya Securities and Nikko Securities merged, and the resulting company used the Nikko Securities trade name.

In 2001, the firm changed its name from Nikko Securities to Nikko Cordial Securities.

In 2007, the firm became a subsidiary of Citigroup after Citigroup purchased Nikko Cordial Corporation forming Nikko Citi Holdings Inc.

In September 2009, Citigroup sold the firm to the Sumitomo Mitsui Banking Corporation.

In 2011, the firm changed its name from Nikko Cordial Securities to SMBC Nikko Securities. In 2016, the firm became a wholly owned direct subsidiary of Sumitomo Mitsui Financial Group.

In 2018, the firm merged with SMBC Friend Securities, while continuing to use the SMBC Nikko Securities trade name.