Louis Hall Nelson (September 17, 1902 – April 5, 1990) was a New Orleans jazz trombonist.

Louis Nelson was born on September 17, 1902 at 1419-21 Touro Street in New Orleans, Louisiana. His father, Dr. George Harry Nelson, was a medical doctor. Dr. Nelson helped organize the 9th Louisiana Volunteers and served in the Spanish–American War. He was commissioned as first lieutenant. During the war he served in Cuba and also stormed San Juan Hill. His mother, Anna Hattie Adams Nelson, was a teacher and pianist from Springfield, Massachusetts. She was a descendant of runaway slaves from the Eastern Shore of Maryland. She was a graduate of the Boston Conservatory of Music. His mother moved to Louisiana to teach and this is where she met her husband. They had three children: Mary Nelson Welch, George Harry Nelson Jr., and Louis Hall Nelson. Both parents and his sister played the piano and his brother played the saxophone. In December 1902, his parents moved to Napoleonville, Louisiana because his father couldn’t get medical patients after the July 1900 Robert Charles Race Riots in New Orleans.

At the age of fifteen, while living in Napoleonville, Louis Nelson started playing the valve trombone and switched to the slide trombone, studying under Professor Claiborne Williams of Donaldsonville, Louisiana. He credited Professor Claiborne Williams with teaching him the proper way to breathe. Williams also taught him that technique and intuition were far more important than technical skill. Nelson is quoted as saying “I heard a fellow, Lawrence Johnson, playing with a band out of Napoleonville. I said, one day I’m going to play trombone like that man. He had a smooth tone, and gave the notes the full value. That’s why I followed in his footsteps.”

Weekdays, Louis Nelson lived with Reverend Isaac H. Hall in New Orleans, Louisiana. Reverend Hall was a family friend who had raised Nelson’s father. While living there, Nelson attended the Lutheran School on Annette Street and New Orleans University (high school) on Saint Charles Avenue in New Orleans, being graduated in 1919.