Julia A. Greenhalgh (later Merrill, born 6 January 1941) was an English amateur golfer. She was runner-up in the 1978 Ladies' British Open Amateur Championship. She won the Ladies' British Open Amateur Stroke Play Championship in 1974 and 1975 and the English Women's Amateur Championship in 1966 and 1979. She played in the Curtis Cup five times, in 1964, 1970, 1974, 1976 and 1978.