Bryan Johnson (ব্রায়ান জনসন) is an American entrepreneur, venture capitalist, writer and author. He is the founder and former CEO of Kernel, a company creating devices that monitor and record brain activity, and OS Fund, a venture capital firm that invests in early-stage science and technology companies.

Johnson was also the founder, chairman and CEO of Braintree, a company specializing in mobile and web payment systems for e-commerce companies. Braintree acquired Venmo in 2012 for $26.2 million; the combined entity was acquired by PayPal for $800 million in 2013.

Johnson was born in Provo, Utah, and raised in Springville, Utah, as a middle child with a brother and a sister. After his parents divorced, Johnson lived with his mother and his stepfather, who owned a trucking company. At 19, Johnson became a Latter-day Saint missionary, customary for young men in the Church of Jesus Christ of Latter-day Saints, and spent two years in Ecuador.

Johnson graduated with a Bachelor of Arts in International Studies from Brigham Young University in 2003 and a Master of Business Administration from the University of Chicago Booth School of Business in 2007.

Johnson has three children from a previous marriage. After that marriage ended he had a relationship with internet personality Taryn Southern. The two were engaged but broke up after she won a battle against breast cancer. Following the breakup, Southern filed a civil lawsuit making various claims, including breach of contract and emotional distress. Because of a contract signed when she was employed by Johnson's company Kernel, the claims had to go through arbitration. The arbitrator dismissed her employment-related claims and ordered Southern to pay Johnson's legal fees. Johnson denied the allegations and addressed the case in a YouTube video released in December 2023.

He was raised and remained a member of the Church of Jesus Christ of Latter-day Saints until he was 34. Bryan Johnson follows a vegan diet.