- "Financial Handbook" (1922)
- "Income Tax Procedure" (1926)
- "Personal Finance" (1934)
- "Montgomery's Manual of Federal Taxes" (1937)
- "Federal Taxes on Estates, Trusts, and Gifts" (1948)
- "Federal Tax Handbook" (1957)
- "Tax Exempt Securities and the Investor" (1959)
- "Montgomery's Federal Taxes—Corporations and Partnerships" (1962)
- "Tax Sheltered Investments" (1966)
- "Robert Montgomery's Tax Strategy" (1968)
Novels and Short Stories:
- "The Gray Angel" (1925)
- "Death to Slow Music" (1926)
- "Three Times Your Name" (1927)
- "The Case of Mrs. Surratt" (1928)
- "The Big Cage" (1929)
- "The Case of Colonel March" (1930)
- "Double for Death" (1931)
- "Here Are to You" (1932)
- "Murder à la Richelieu" (1933)
- "To Love and to Live" (1934)
Poetry:
- "Ballads of Battle" (1914)
- "Mount Vernon Poems" (1918)
- "For a Woman and Other Poems" (1922)
- "The Last Man at Gettysburg and Other Poems" (1941)