The exercise is part of a series of bilateral naval exercises between the US Navy and the armed forces of nine partner nations in South and Southeast Asia.
It is aimed to develop strong maritime partnerships that will support achieving peace and stability in the region.
CARAT Singapore 2015 will include both shore and sea phases, featuring complex scenarios with ships, submarines, and aircraft, as well as a combined torpedo exercise.
Task Force 73 commander rear admiral Charlie Williams said: "This marks the 21st year that the US and Singapore Armed Forces have come together for CARAT, and our enhanced military partnership today reflects the maturity of this relationship.
"CARAT Singapore provides our forces with a complex and dynamic training environment that continues to increase our combined capabilities."
The shore phase of the exercise will include classroom and field training events, an aviation symposium, visit, board, search, and seizure drills, as well as submariner classroom exchanges, military medicine classes, and military law enforcement training.
The exercise, which will conclude on 24 July, will see participation of more than 700 US sailors and marines.
After the completion of CARAT Singapore, the US Navy will conduct CARAT exercise with Bangladesh, Brunei, Cambodia, Indonesia, Malaysia, Thailand and Timor-Leste.
In June, the US Navy carried out CARAT Philippines exercise series, focusing on combined operations at sea and maritime domain awareness.
Image: The littoral combat ship USS Fort Worth (LCS 3) will participate in CARAT Singapore 2015. Photo: courtesy of US Navy photo by mass communication specialist 2nd Class Joe Bishop / Released.