On 1 July 1918, Santa Olivia was acquired by the Navy and commissioned at Philadelphia as USS Santa Olivia (SP-3125), with Lieutenant Commander George H. Miles, USNRF, placed in command.

 
Santa Olivia was assigned to the Naval Overseas Transportation Service (NOTS) upon commissioning.
Departing from Philadelphia on 15 July 1918 for New York, the ship made two round-trip voyages to Europe before the war's end on 11 November 1918.
Sailing from New York each time, she carried a total of 10,773 tons of general cargo to Marseilles.

With the war over, the foreign contingent of the American Cruiser and Transport Force withdrew, obliging the U.S. Navy to undertake a rapid expansion of its fleet of troop transports in order to quickly repatriate U.S. forces from France.
A total of 56 ships were selected for conversion to troopships, including Santa Olivia.
Santa Olivia was detached from NOTS on 20 December 1918 and recommissioned as a troop transport the same day.
Between 26 December 1918 and 14 February 1919, Santa Olivia was converted to a troop transport by the W. & A. Fletcher Company of Hoboken, New Jersey, at a cost of $150,778.
After conversion, the ship had a troop capacity of 32 officers and 1,825 enlisted men, and a crew complement of 21 officers and 168 enlisted men.

Reassigned to the Cruiser and Transport Force, Atlantic Fleet, Santa Olivia embarked on the first of four troop transport missions between the U.S. and France on 16 February 1919, departing New York for Brest, the return voyage being made from 18 to 30 March.
Her second such voyage to France returned to Philadelphia on 12 May, with 30 officers and 1,825 men of the 110th Infantry Regiment and three officers of the 178th Machinegun Detachment.
The 110th Infantry was described as "the hardest hit of the National Guard regiments", having lost 500 killed and 3,000 wounded in the war.
Returning to France, Santa Olivia sailed from Bordeaux on May 30 with 1,891 troops, including 16 officers and 429 men of C and D companies, 303rd Engineers, 78th Division, arriving New York 10 June.

Santa Olivia's final round trip to France for the navy began with a departure from New York on 15 June.
At Bordeaux, Santa Olivia embarked another 45 officers and 1,814 men, returning them to New York on 9 July.
During this voyage, the ship experienced some rough weather causing a planned onboard Fourth of July celebration to be postponed until the 6th, while two soldiers and one sailor were confined after showing "signs of insanity"; the three men were later transferred to a military hospital for observation.
Santa Olivia was the last U.S. troopship to depart from Bordeaux, the port subsequently being abandoned as a U.S Navy embarkation point in favor of Brest.
In her four troop repatriation missions, Santa Olivia returned a total of 7,491 officers and men to the United States, including 14 sick or wounded.
On 21 July, Santa Olivia was decommissioned at the Grace Line Pier, Brooklyn, and returned the same day to her owner, W. R. Grace & Co.
A teenage Humphrey Bogart served on USS Santa Olivia in 1919 as a coxswain.
After being transferred from USS Leviathan (SP-1326) in February, Bogart missed an April sailing of Santa Olivia, but avoided being listed as a deserter by reporting for duty within hours.
He was given three days' solitary confinement on bread and water for going AWOL, but the incident did not affect his service record.
After returning to the ship, he was honorably discharged on 18 June 1919 with high marks for proficiency and sobriety.

Santa Olivia's commander during her naval service, George H. Miles, would later run afoul of the law.
In 1922, while captain of SS President Van Buren, Miles was charged with murder for beating a deranged pantryman, who died the following day.
Convicted of "inhumane treatment", Miles was sentenced to 18 months' jail over the incident and lost his masters' licence.
In February 1923, while out on bail pending an appeal of his conviction, Miles was arrested for alleged bootlegging.
In 1930, Miles was again arrested by police, for attempted bur
On 1 July 1918, Santa Olivia was acquired by the Navy and commissioned at Philadelphia as USS Santa Olivia (SP-3125), with Lieutenant Commander George H. Miles, USNRF, placed in command. 
 
Santa Olivia was assigned to the Naval Overseas Transportation Service (NOTS) upon commissioning. Departing from Philadelphia on 15 July 1918 for New York, the ship made two round-trip voyages to Europe before the war's end on 11 November 1918. Sailing from New York each time, she carried a total of 10,773 tons of general cargo to Marseilles.
With the war over, the foreign contingent of the American Cruiser and Transport Force withdrew, obliging the U.S. Navy to undertake a rapid expansion of its fleet of troop transports in order to quickly repatriate U.S. forces from France. A total of 56 ships were selected for conversion to troopships, including Santa Olivia. Santa Olivia was detached from NOTS on 20 December 1918 and recommissioned as a troop transport the same day. Between 26 December 1918 and 14 February 1919, Santa Olivia was converted to a troop transport by the W. & A. Fletcher Company of Hoboken, New Jersey, at a cost of $150,778. After conversion, the ship had a troop capacity of 32 officers and 1,825 enlisted men, and a crew complement of 21 officers and 168 enlisted men.
Reassigned to the Cruiser and Transport Force, Atlantic Fleet, Santa Olivia embarked on the first of four troop transport missions between the U.S. and France on 16 February 1919, departing New York for Brest, the return voyage being made from 18 to 30 March. Her second such voyage to France returned to Philadelphia on 12 May, with 30 officers and 1,825 men of the 110th Infantry Regiment and three officers of the 178th Machinegun Detachment. The 110th Infantry was described as "the hardest hit of the National Guard regiments", having lost 500 killed and 3,000 wounded in the war. Returning to France, Santa Olivia sailed from Bordeaux on May 30 with 1,891 troops, including 16 officers and 429 men of C and D companies, 303rd Engineers, 78th Division, arriving New York 10 June.
Santa Olivia's final round trip to France for the navy began with a departure from New York on 15 June. At Bordeaux, Santa Olivia embarked another 45 officers and 1,814 men, returning them to New York on 9 July. During this voyage, the ship experienced some rough weather causing a planned onboard Fourth of July celebration to be postponed until the 6th, while two soldiers and one sailor were confined after showing "signs of insanity"; the three men were later transferred to a military hospital for observation. Santa Olivia was the last U.S. troopship to depart from Bordeaux, the port subsequently being abandoned as a U.S Navy embarkation point in favor of Brest. In her four troop repatriation missions, Santa Olivia returned a total of 7,491 officers and men to the United States, including 14 sick or wounded. On 21 July, Santa Olivia was decommissioned at the Grace Line Pier, Brooklyn, and returned the same day to her owner, W. R. Grace & Co.
A teenage Humphrey Bogart served on USS Santa Olivia in 1919 as a coxswain. After being transferred from USS Leviathan (SP-1326) in February, Bogart missed an April sailing of Santa Olivia, but avoided being listed as a deserter by reporting for duty within hours. He was given three days' solitary confinement on bread and water for going AWOL, but the incident did not affect his service record. After returning to the ship, he was honorably discharged on 18 June 1919 with high marks for proficiency and sobriety.
Santa Olivia's commander during her naval service, George H. Miles, would later run afoul of the law. In 1922, while captain of SS President Van Buren, Miles was charged with murder for beating a deranged pantryman, who died the following day. Convicted of "inhumane treatment", Miles was sentenced to 18 months' jail over the incident and lost his masters' licence. In February 1923, while out on bail pending an appeal of his conviction, Miles was arrested for alleged bootlegging. In 1930, Miles was again arrested by police, for attempted bur
USS Santa Olivia