Alexander Robert Reinagle (1756 – 1809) was an English-born American composer, organist and theater musician. He was born in Portsmouth, England. His father was a Hungarian professional musician and his mother was Scottish.
He studied music with his father and then with Raynor Taylor in Edinburgh. He made a trip to London in 1763. He met Mozart and his family a year later. Reinagle first made a living in shipping, making several trips to the American colonies in the 1770s. In Edinburgh, he taught music and gave several concerts.
His earliest compositions, dating from his time in Edinburgh, include a set of duets for two cellos, Opus 2, and Variations on famous Scottish melodies, published in Glasgow and later in Philadelphia.