Lucas v. Earl, 281 U.S. 111 (1930), is a United States Supreme Court case concerning U.S. Federal income taxation, about a man who reported only half of his earnings for years 1920 and 1921.

Guy C. Earl and his wife had entered into a contract that would potentially save a lot of tax.

[1] The case is used to support the proposition that the substance of the transaction, rather than the form, is controlling for tax purposes.

[2] Guy C. Earl was an attorney who entered into a contract with his wife whereby all property and earnings were to be "treated and considered .

"[8] Holmes concludes his opinion with the classic metaphor: The fruits cannot be attributed to a different tree from that on which they grew.