Internships in Fullerton, California, United States

RTX invites students to join its Connected Aviation group as a Software Engineer Intern for the summer of 2026. Based in Fullerton, California, the role is on‑site and offers hands‑on experience in developing the Wide‑Area Augmentation System (WAAS) for the FAA. Interns will design, code, test, and document new or modified software, collaborating with developers, testers, release engineers, and cross‑disciplinary teams such as systems and hardware.

Volunteer/Internship – Law Student Externship at the Superior Court of Orange County offers law students an unpaid, hands‑on experience in legal research and memorandum drafting. Externs work behind the scenes, supporting judges and clerks with civil, criminal, family, and juvenile matters.

RTX is seeking a Systems Engineering Intern to join the Multidisciplinary Integrated Systems Department in Fullerton, CA. The role focuses on modeling and simulation for space-based systems and satellites, contributing engineering practices to solve complex computational problems. Interns will identify and update circuit card and subassembly designs, and may travel to suppliers.

Seneca Family of Agencies offers immersive fieldwork placements for MSW, MFT, and PCC interns across Southern California. The program follows a standard academic calendar, beginning in the fall and concluding in spring/summer, with a minimum commitment of 16 hours weekly—some sites require 20‑24 hours.

Rosendin Electric, a leading electrical contractor, offers a Summer Internship Program for Civil Engineering students. The 10‑to‑12 week paid internship provides hands‑on experience in Construction Project Management, Engineering, Procurement, Estimating, Safety, and Corporate roles.

The Veterinary Emergency Group (VEG) offers an unpaid externship for veterinary technology students to gain hands‑on experience in emergency medicine. Participants shadow credentialed technicians, assist with triage, diagnostics, anesthesia, and inpatient care, and receive mentorship.

Uline is seeking a motivated college student for a paid Outside Sales Internship during Summer 2026. The role offers hands‑on experience in face‑to‑face selling, weekly sales training, and mentorship from seasoned sales professionals.

Industrial Engineering Intern at UPS will conduct operational observations, analyze data, develop reports, and support process improvement projects to reduce costs. Responsibilities include identifying business impacts, recommending and implementing process improvements with analysts and sponsors, and preparing presentations and reports.

This internship offers hands‑on experience in industrial engineering at UPS. The role involves field observations, data analysis, and report creation to support process‑improvement projects. Interns will research data, develop queries, and prepare presentations that help reduce costs and enhance operational efficiency.

Event Operations Intern at OC Sports & Entertainment, LLC. The role supports the Honda Center’s live entertainment team, coordinating event orders, interdepartmental communication, and day‑of‑show logistics to deliver safe, memorable experiences. Interns work on‑site in Anaheim, assisting with planning, promotion support, and operational documentation while gaining exposure to venue management systems and budgeting.

Northwestern Mutual College Financial Representatives internship program builds future financial planners through hands‑on mentorship and proprietary planning tools. Interns prospect and network to grow client bases, develop business strategies, and prepare financial plans while engaging weekly coaching and training sessions.

Fellowship of Christian Athletes (FCA) interns develop student athletes’ calling to ministry while engaging in a 10‑week immersive discipleship program. The role involves spiritual leadership, prayer, Bible study, and coaching support for athletes and volunteers in Southern California.

An internship and co‑op opportunity at Marathon Petroleum Corp. (MPC) offers high‑performing college students in Civil, Electrical, or Mechanical Engineering hands‑on experience in the Logistics & Storage organization.

Harbinger Motors Marketing Team drives brand growth and market expansion for the next‑generation medium‑duty electric vehicles. The Marketing Intern supports event planning, content creation, campaign operations, and cross‑functional collaboration to boost lead generation and dealer enablement.

Product Marketing team at Microchip Technology enables key product marketing activities for the High Reliability Analog and Power division. The intern creates and manages collateral, conducts market analysis, supports go‑to‑market plans, and contributes content for product promotion while collaborating across teams.

STRUCTURAL, a leading concrete repair contractor, offers a Construction Project Engineer Internship for Summer 2025 in Garden Grove, CA. The role involves project management support, estimating, budgeting, cost management, scheduling, production tracking, client relations, safety, quality control, and business development. Candidates should have a Bachelor's degree or be pursuing one in Construction Management, Civil Engineering, or related field, strong communication, documentation, organizatio

Power Electronics Team at Harbinger Motors, developing electric vehicle power systems. The intern assists with design, testing, and validation of inverters, chargers, and converters, creates PCB layouts, runs simulations, and documents results.

Production Finance team at Harbinger Motors, building scalable financial processes for EV manufacturing and launch. The intern supports reporting, analytics, and automation across finance, manufacturing, quality, and logistics, creating models, dashboards, and process documentation.

An internship/co‑op opportunity with Marathon Petroleum’s Logistics & Storage organization offers hands‑on experience in engineering design, project management, cost estimating, scheduling, bid evaluation, construction supervision, safety leadership, and operations coordination. Interns rotate across L&S components—Support Services, Terminals, MPL, and Marine—to gain exposure to pipeline, terminal, and marine operations.

First American’s Data & Analytics division offers a 10‑12 week paid internship for graduate students in AI/Data Science. Interns work with data scientists, engineers, and subject matter experts to build property valuation and collateral analytic models using nationwide property data.