James B. Lynch (died 12 March 1954) was an Irish Fianna Fáil politician, who served for 16 years as a Teachta Dála (TD) before being elected as a Senator for three years.
A physician and surgeon before entering politics, Lynch was elected to Dáil Éireann on his first attempt, at the 1932 general election, when he stood as a Fianna Fáil candidate in the 7-seat Dublin South constituency. He was the last candidadte to be elected, and took his seat in the 7th Dáil.
He was returned to the 8th Dáil at the 1933 election, but did not contest the 1937 general election. He stood again at the 1938 general election, was returned to the 8th Dáil. He retained his seat at the next two general elections, but when constituency boundaries were revised at the 1948 general election, he stood in the neighbouring Dublin South Central and was not elected. He stood again in Dublin South Central at the 1951 general election, but lost again.
He then stood in the 1951 election to Seanad Éireann, winning won a seat on the Cultural and Educational Panel in the 7th Seanad, where he served until 1954. His wife, Celia Lynch, was a TD for Dublin South Central from 1954 to 1977.