The United States Senate election of 1788 were the first elections for the United States Senate, which coincided with the election of President George Washington. As of this election, formal organized political parties had yet to form in the United States, but two political factions were present: The coalition of Senators who supported George Washington's administration were known as the Pro-Administration Party, and the Senators against him as the Anti-Administration Party.

As this election was prior to the seventeenth amendment, Senators were chosen by State legislatures.

Senate composition

Senators seated at the beginning the 1st Congress 1st United States Congress -House of Representatives:During this congress, five House seats were added for North Carolina and one House seat was added for Rhode Island when they ratified the Constitution.-Senate:* President: John Adams * President pro tempore: John Langdon...
									A1
P12	P13	V	V	A7	A6	A5	A4	A3	A2
P11	P10	P19	P8	P7	P6	P5	P4	P3	P2
									P1

Two seats were vacant because New York elected its senators late.

Senate at the end of the 1st Congress 1st United States Congress -House of Representatives:During this congress, five House seats were added for North Carolina and one House seat was added for Rhode Island when they ratified the Constitution.-Senate:* President: John Adams * President pro tempore: John Langdon...
							A1	A2	A3
P14	P15	P16	P17	P18	A8	A7	A6	A5	A4
P13	P12	P11	P10	P9	P8	P7	P6	P5	P4
							P1	P2	P3

Four seats were filled late because North Carolina and Rhode Island ratified the Constitution late.

Key:	A = Anti-Administration Anti-Administration Party (United States) Anti-Administration "Party" was the informal faction comprising the opponents of the policies of Treasury Secretary Alexander Hamilton in the first term of President George Washington. This was not an organized political party but an unorganized faction...	P = Pro-Administration Pro-Administration Party (United States) Pro-Administration "Party" is a term by historians to describe the supporters of the policies of George Washington's administration — especially Treasury Secretary Alexander Hamilton's financial policies — prior to the formation of the Federalist and Democratic-Republican Parties.Almost the entire...	V= Vacant