Khalil went to the Pingry School, an exclusive prep school in New Jersey. He went on to attend Columbia University where he earned a Bachelor of Arts in political science and graduated Summa Cum Laude. At Columbia Khalil was a member of the Phi Beta Kappa Society, he took home the Dean Hawkes Memorial Prize in the Humanities, and he graduated on the Dean's list with departmental honors in political science. Khalil then attended Stanford Law School where he earned a Doctor of Jurisprudence and spent some time as a U.S attorney extern. 
While he was in college Khalil held various positions that would influence the course of his career. He was a congressional intern for Rep. Rush Holt Jr., 12th District of New Jersey, a technical auditing intern with the R.W. Johnson Pharmaceutical Research Institute, Johnson & Johnson, a research assistant at Columbia University's Department of Political Science, a research assistant at Columbia University's Institute for Social and Economic Research and Policy, a policy intern for the New York City Public Advocate, and a teaching assistant at Stanford University. 
Fresh out of school Khalil became a student practice certified law clerk in the tax division of the U.S. Attorney's Office, Northern District of California. He spent his time representing the government in federal tax cases. Khalil moved on to Sullivan & Cromwell representing financial institutions in non-public regulatory and criminal investigation, managing summer law clerks in pro bono matters, and much more.
Khalil then worked for Mayer Brown as an attorney litigating complex commercial and securities case in addition to representing high-level corporate executives in regulatory investigations. Two years later Khalil became founder and director of Northwest Mediation LLC. He managed all company operations, arbitrated and mediated commercial and individual disputes, provided dispute resolution and conflict management consulting services to organizations and individuals, he also served on Financial Industry Regulatory Authority and Better Business Bureau arbitration panels.
In April of 2019 he started the Khalil For Congress campaign, running for the U.S. House of Representatives, 3rd District of Washington. The main issues that he throws his energy behind are healthcare, environment, infrastructure, regulation of Wall Street, clean campaign finance, affordable housing, identity politics, gun violence, immigration, criminal justice reform, women's rights, military, education, and senior citizens. 
Peter's father grew up in a village in Upper Egypt and studied chemistry and geology at Alexandria University. After facing discrimination as a Coptic Christian, Peter's father immigrated from Egypt to the United States in 1969 with $200 in his pocket. He soon met his wife, a fellow Coptic Christian who studied engineering at Cairo University and settled in High Bridge, New Jersey in 1974. Peter's parents invested in his future, borrowing against their house to send him to prep school.
Khalil's wife grew up in Ridgefield, Washington and they met at law school. They moved together to Clark County and had a son named Adrian. Peter is an active volunteer in the community, he's coached Mock Trial at Ridgefield High School and has helped socialize guide dogs for the blind for Guide Dogs of America.