Peter Brotherhood (1838–1902) was an English engineer. He invented the Brotherhood engine used for torpedoes as well as many other engineering products.

With his son he built a large engineering business in London bearing his name, Peter Brotherhood. His son Stanley moved the works to Peterborough in 1903 where their engineering business continued to grow.

Brotherhood was the second son of the 14 children of Priscilla (née Penton) and Rowland Brotherhood (1812-1883), an English engineer. He was born in Maidenhead, Berkshire on 22 April 1838 and raised in comfortable circumstances in Chippenham, Wiltshire near his father's engineering works.

From the ages of 13 to 18, he studied applied science at King's College School. After practical experience including a period at the Great Western Railway's Swindon Works he joined the leading marine engineering works, Maudslay, Son & Field in Lambeth in their drawing-office.

In 1861 Brotherhood built the 15-inch gauge model steam locomotive 'Pearl' which is on display at the Strand Campus of King's College London and is understood to be the oldest large-scale model railway engine in existence.

He is said to have had a "mechanical instinct" which allowed him to design machinery without resorting to calculations or formulae. He also had a passion for experimentation.

On 19 April 1866, he married Eliza Pinniger Hunt, daughter of James Edward Hunt a contractor to the Indian Railways. Together they had five children, two daughters and three sons, two of his sons predeceased him.

Brotherhood died at his home 15 Hyde Park Gardens on 13 October 1902.