Johannes F. Linn was born on October 22, 1945 near Munich, Germany. He studied law at the Free University in Berlin before receiving a Bachelor of Arts in philosophy, politics, and economics from Oxford University in 1968 and a PhD in economics from Cornell University in 1972.

Linn joined the World Bank on January 2, 1973 as a Young Professional. During his first nine years of employment at the Bank, he was an economist in the Urban and Regional Economics Division in the Economics Department (ECDRB) and its successor the Development Economics Department (DEDRB) of the Development Policy Vice Presidency (DPS), the Bank's research unit. During this time he focused on issues of urban development policy. In 1978 Linn spent six months as a visiting researcher at the University of Munster.

In 1981, Linn moved to the operations side of the Bank when he was named Senior Economist in the East Asia and Pacific Vice Presidency's (AENVP) Division A (AEADA), which was responsible for Democratic Kampuchea, Lao People'sDemocratic Republic (PDR), Mekong Committee, Thailand, Vietnam, and liaison with the United Nations Economic and Social Commission for Asia and the Pacific (ESCAP). In 1984 he was named a Senior Economist in the AENVP's Country Programs Department's Office of the Director (AEADR). Following the 1987 Bank-wide reorganization that combined the AENVP and the South Asia Vice Presidency (ASNVP) into a single Asia Regional Vice Presidency (ASI), Linn became the Lead Economist in the Country Department responsible for Burma, Democratic Republic of Kampuchea, Korea, Lao PDR, Malaysia, Mekong Committee, Philippines, Thailand, and Vietnam (AS2).

In 1987, Linn was named Staff Director of the World Development Report 1988 (WDR). The WDR focused on public finance policies for development and reviewed trends in this sector in the world economy. He began this work within ASI but appears to have given up many of his responsibilities as Senior Chief Economist of the Region in order to focus on the WDR. In 1988 Linn returned to the research arm of the Bank when he was named Senior Economic Advisor in the Development Economics Vice Presidency (DECVP). He subsequently served as Director of DECVP's International Economics Department (IEC, 1989-1990), which focused on international finance, and trade and, between 1990 and 1991, Director of DECVP's Country Economics Department (CEC), which led country development policy design and analysis activities.

In December of 1991 Linn succeeded Joseph Wood as Vice President of the Financial Policy and Risk Management Vice Presidency (FPRVP) that contained the Risk Management and Financial Policy Department (FRS) and the Resource Mobilization Department (FRM). During this time Linn oversaw various finance-related functions including: financial policy and management; IBRD capital resource mobilization; and IDA replenishment. Linn served in this position for five years.

In 1996 Linn was named Regional Vice President of the Europe and Central Asia Vice Presidency (ECAVP).

Linn remained ECA Vice President until 2003 when he retired from the World Bank after thirty years. He frequently returned to the Bank as a consultant in subsequent years, most often for the ECAVP and the Independent Evaluation Group (IEG).

From 2003 to 2006 Linn was a Visiting Fellow at the Brookings Institution in Washington, DC and beginning in 2005 he served as an Executive Director for the Wolfensohn Center at Brookings. As of 2016 Linn is a Nonresident Senior Fellow in the Global Economy and Development Program at theBrookings Institution where his research focusses on aid effectiveness, global governance reform, and regional cooperation.