Andreas Maria Maximilian Freiherr von Mauchenheim genannt Bechtolsheim (born 30 September 1955) is a German electrical engineer, entrepreneur and investor. He co-founded Sun Microsystems in 1982 and was its chief hardware designer. As of 2025,^[update] he's 68th wealthiest according to Bloomberg Billionaires Index and Forbes with an estimated net worth of US$28.9 billion.

Bechtolsheim was born at Hängeberg am Ammersee, located in Finning, Landsberg, Bavaria, the second of four children. The isolated house had no television or close neighbors, so he experimented with electronics as a child. His family moved to Rome in 1963. Five years later, in 1968, the family relocated again, to Nonnenhorn on Lake Constance in Germany. At age 16, he designed an industrial controller for a nearby company based on the Intel 8008, which he then programmed in binary code as he had no access to assemblers. Royalties from the product supported much of his education.

Bechtolsheim participated in the Jugend forscht competition for young researchers three times and won the physics prize in 1974. He began studying electrical engineering with a focus on data processing at the Technical University of Munich, supported by the German Academic Scholarship Foundation, and graduated with an engineering degree. Frustrated by the limited access to computers and dissatisfied with his studies, he moved to the United States in 1975 with the help of a Fulbright scholarship and earned a master's degree in computer engineering from Carnegie Mellon University in 1976.

In 1977, Bechtolsheim moved to Silicon Valley after receiving an internship offer from Justin Rattner at Intel. When Rattner relocated to Oregon, Bechtolsheim chose instead to enroll at Stanford University as a Ph.D. student in electrical engineering. He left Stanford five years later to pursue opportunities in the technology industry.

At Stanford, Bechtolsheim designed a powerful computer (called a workstation) with built-in networking called the SUN workstation, a name derived from the initials for the Stanford University Network. It was inspired by the Xerox Alto computer developed at the Xerox Palo Alto Research Center. Bechtolsheim was a "no fee consultant" at Xerox, meaning he was not remunerated directly but had free access to the research being done there. At the time, Lynn Conway was using workstations to design very-large-scale integration (VLSI) circuits.

Bechtolsheim's advisor was Forest Baskett. In 1980, Vaughan Pratt also provided leadership to the SUN project. Support was provided by the Computer Science Department and DARPA. The modular computer was used for research projects such as developing the V-System, and for early Internet routers. Bechtolsheim tried to interest other companies in manufacturing the workstations, but only got lukewarm responses.

One of the companies building computers for VLSI design was Daisy Systems, where Vinod Khosla worked at the time. Khosla had graduated a couple of years earlier from the Stanford Graduate School of Business with Scott McNealy, who managed manufacturing at Onyx Systems. Khosla, McNealy and Bechtolsheim wrote a short business plan and quickly received funding from venture capitalists in 1982. Bechtolsheim left Stanford to co-found the company, Sun Microsystems, as employee number one, with McNealy and Khosla, and with Bill Joy, who had been part of the team developing the BSD series of Unix operating systems at UC Berkeley; Bill is usually counted as the fourth member of the founding team. For a while Bechtolsheim and Joy shared an apartment in Palo Alto, California.

The first product, the Sun-1, included the Stanford CPU board design with improved memory expansion, and a sheet-metal case. By the end of the year, the experimental Ethernet interface designed by Bechtolsheim was replaced by a commercial board from 3Com.