Sir Tejinder Singh Virdee, FRS (Punjabi: ਤਜਿੰਦਰ ਸਿੰਘ ਵਿਰਦੀ, born 13 October 1952), is a Kenyan-born British experimental particle physicist and Professor of Physics at Imperial College London.

[8] In 2015 he was awarded the IOP Glazebrook Medal and Prize for his leadership of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) where evidence for the Higgs boson was revealed after 20 years of research involving design, construction and data-taking.

[11] The citation reads: "for extraordinary leadership and profound impact on all phases of the monumental CMS experiment at the CERN Large Hadron Collider, including the crucial discovery of the Higgs boson through its decays to two photons."

After completing his Ph.D. at Imperial College London, on an experiment conducted at the Stanford Linear Accelerator Center (SLAC) in California,[15] he joined CERN in 1979 as a Fellow of the Experimental Physics Division.

Virdee’s early scientific career (1979-1984) involved verifying the strange notion that the “quarks” (the constituents of the protons the neutrons and all other hadrons) carry fractional electric charge.

[16] Following NA14 he joined the UA1 experiment at CERN's proton-antiproton collider (SPS) where his interest in high-performance calorimetry was developed, leading to his invention of a novel technique of collecting light in plastic scintillator-based calorimeters.

[17] Towards the end of UA1, (1990) Virdee, with a few other colleagues, started planning an experiment based on a high field solenoid that would be able to identify the missing elements of the Standard Model (SM) and also to probe in full the physics of the TeV scale.

[17] The possibility of discovering a Higgs-like boson played a crucial role in the conceptual design of CMS,[19][20] and served as a benchmark to test the performance of the experiment.

In 1990 Virdee and a colleague, Christopher Seez, carried out the first detailed simulation studies of the most plausible way to detect the SM Higgs boson in the low-mass region in the environment of the LHC: via its decay into two photons.

In 1994, he made a compelling case for the use of lead tungstate scintillating crystals (PbWO4) for the electromagnetic calorimeter of CMS[23] as being the most promising detector for the discovery of the Higgs boson via its two-photon decay mode.

Virdee is leading efforts to replace the detector's endcaps with a novel silicon-based technology that measures the energy and momentum of particles to unprecedented levels of precision.