John Thomson Dallas (April 15, 1880 – December 4, 1961) was the fifth Bishop of New Hampshire in the Episcopal Church from 1926 to 1948.

He commenced studies in the Union Theological Seminary and graduated in 1908.

After ordination he served as curate at St John's Church in Waterbury, Connecticut.

In 1920 he was also appointed as rector of St Thomas' Church in Hanover, New Hampshire.

In 1925, he was transferred as vicar of St Paul's Cathedral in Boston.