The 103rd Regiment of Foot (Royal Bombay Fusiliers), "the Old Toughs", was an infantry regiment of the British Army from 1862 to 1881, when it was amalgamated into The Royal Dublin Fusiliers.

The regiment was originally raised in England in 1662 as independent companies of European soldiers to garrison Bombay, newly ceded to the British crown, and were transferred to the Honourable East India Company, under the title The Bombay Regiment, when they leased Bombay in 1668. They were numbered the 1st Bombay (European) Regiment on the foundation of a second European regiment in 1839, and designated the 1st Bombay (European) Fusiliers in 1844. As with all other "European" units of the Company, they were placed under the command of the Crown in 1858, and formally moved into the British Army in 1862, ranked as the 103rd Foot.

As part of the Childers Reforms in 1881, the regiment was amalgamated with the 102nd Regiment of Foot (Royal Madras Fusiliers) to form The Royal Dublin Fusiliers.

References

• Includes chronological index of titles.