The Colony War in Starfield ended in the year 2311. The war lasted from around 2308 to 2311, culminating in the decisive Battle of Cheyenne where the Freestar Collective defeated the United Colonies, leading to the war's conclusion

. Key points about the end of the Colony War:

• The final battle occurred in 2311, where the Freestar Collective used hit-and-run tactics and support from armed civilian ships to defeat the United Colonies' fleet

• After this defeat, the United Colonies surrendered and peace was established, with military leaders from the United Colonies put on trial for war crimes

• The war's end led to a treaty banning the use of mechs and xenoweapons by both factions, and a tense peace existed between them at the start of the game in 2330

Thus, the Colony War officially ended in 2311.