Giuseppe Baldassare Sammartini (January 6, 1695 - November 1750) was an Italian composer and an oboist.
A native of Milan, he moved to London together with his brother Giovanni Battista Sammartini. He had started playing the oboe in Milan and in London took up the post of oboist in the Opera orchestra in 1727. He later left the Opera and was patronised by Frederick, Prince of Wales and his wife. He served them as Musical Director of the Chamber Concerts and was a member of their household.
Sammartini's compositions included sonatas for flute and violin, sonatas for 2 flutes with thoroughbass, 12 sonatas for violin (dedicated to the Princess of Wales) 6 concertos for violin, concerto grossos, harpsichord concertos, 6 solo pieces for the German flute and 6 sonatas for 2 German flutes and violins. He also composed a number of lively pieces for cello, such as 'Movement D'une Seranade.