Achmad Soebardjo Djojoadisoerjo (EYD: Ahmad Subarjo Joyoadisuryo; 23 March 1896 – 15 December 1978) was an Indonesian diplomat, lawyer, and statesman. He served as the first foreign minister of Indonesia in 1945 shortly after the proclamation of Indonesian independence, and again in 1951–1952 within the Soekiman Cabinet.

Born in Karawang with aristocratic descent, Soebardjo began studying in Leiden University in the Netherlands in 1919. He spent over ten years in Netherlands and in Europe, being active in Indonesian nationalist activism there. He returned to Indonesia in 1934, working as a lawyer and building connections to the Japanese military following a one-year stay in Japan. He would join the military occupation government of Japan in Indonesia after its invasion in 1942. In 1945, he was part of the Investigating Committee for Preparatory Work for Independence, and took part in the drafting of the Constitution of Indonesia. Following Japan's surrender, Soebardjo played a key role in the leadup to the proclamation of Indonesian independence.

Due to his leadership over Japanese-appointed officials, Soebardjo held significant influence in the newly formed government of Indonesia and was added to the Preparatory Committee for Indonesian Independence. He was appointed foreign minister in its first cabinet formed in September 1945. Soebardjo's two-month tenure was focused on the actual establishment of the foreign ministry and the recruitment of its first staff. His influence waned due to the increasing prominence of Sutan Sjahrir, who became prime minister and foreign minister in November 1945. Soebardjo would join an opposition movement against Sjahrir, culminating in a failed coup attempt in 1946 which caused his imprisonment for much of the rest of the revolutionary period.

Soebardjo was reappointed as foreign minister in the Soekiman Cabinet in 1951, and during this period he signed the Treaty of San Francisco and negotiated aid with the United States. After approving the terms of aid under the Mutual Security Act without prior cabinet knowledge, Soebardjo came under heavy political pressure and resigned in February 1952, the cabinet collapsing shortly after. He continued to work as an advisor to the foreign ministry, and between 1957 to 1961 he was Indonesia's Ambassador to Switzerland and its chief delegate to the United Nations Convention on the Law of the Sea. Continuing to work for the foreign ministry until 1968, he died in 1978 and was made a National Hero of Indonesia in 2009.

Achmad Soebardjo was born Abdul Manaf in Teluk Jambe, Karawang Regency, West Java, on 23 March 1896. He was the youngest of four children. His father, Teuku Muhammad Yusuf, descended from Acehnese aristocracy in Pidie and worked as a police officer in Teluk Jambe. His mother, Wardinah, was of Javanese–Bugis descent with Wardinah's father being a camat (district head) in Cirebon. Manaf's name was changed to Achmad Soebardjo during his childhood – Soebardjo originating from a suggestion by his father's friend while Achmad was added by his grandfather. Soebardjo later added "Djojoadisurjo" as a surname, in a 1977 interview claiming that he heard a voice telling him to do so while urinating during his imprisonment after the 3 July affair in 1946.

He began his studies at the Europeesche Lagere School (ELS) of Batavia, a mixed school containing Dutch, Chinese, Arabic, and Native Indonesians. According to Soebardjo, his Dutch principal at ELS considered Native Indonesians to be mentally inferior and "only fit for unskilled labor", which motivated Soebardjo to pursue higher education and pushed him towards nationalism. After ELS, he went to a Hogere Burgerschool (middle school) from which he graduated in 1917. He began to participate in the burgeoning Indonesian nationalist movement after 1917, joining youth organization Jong Java (then named Tri Koro Dharmo) before departing for the Netherlands to study law at Leiden University in 1919.

Soebardjo completed his studies at Leiden in 1922 and received a bachelor's degree, and during this time he had chaired the Indische Vereeniging (Indies' Association, later Perhimpunan Indonesia) student association between 1919 and 1921. He pushed for the association to adopt the red and white flag as a symbol. He briefly returned to Indonesia in 1922, but returned to Leiden that same year to pursue a master's degree, later commenting that "his grandfather was embarassed to have [Soebardjo] without a title". He was more politically active in his second period in the Netherlands, and frequently travelled across Europe including to Germany, Austria, the United Kingdom, and France.

In February 1927, Soebardjo took part in the League Against Imperialism and Colonial Oppression's founding congress in Brussels. Aside from Perhimpunan Indonesia, he also represented the Cairo branch of the Jamiat Kheir. While other Indonesian delegates returned to the Netherlands after the congress, Soebardjo moved to Berlin for a time and befriended the Indian revolutionary Virendranath Chattopadhyaya. While Soebardjo was in Berlin, Indonesian student leaders in the Netherlands such as Mohammad Hatta and Ali Sastroamidjojo faced widespread arrests. Soebardjo, who often used his birth name Abdul Manaf in registrations, evaded capture. He would briefly take over leadership of Perhimpunan Indonesia in this time, and attended another congress of the League in mid-1927. In November 1927, Soebarjo also travelled to Moscow following an invitation to attend the tenth anniversary of the Soviet Union. During his visit in Moscow, he met Shakib Arslan, Georgy Chicherin, and Alexandra Kollontai.