Two-dimensional monolayer pentagonal silicon dicarbide (pSiC2) and its one-dimensional nanoribbon derivative (pSiC2NR) possess novel electronic properties, possibly leading to many potential applications. In this chapter, we have systematically investigated the structural, electronic, and transport properties of pSiC2NRs using chemical function and strain engineering. The energy gaps of the pSiC2NRs (ZZ-ribbon, ZA-ribbon, AA-ribbon, and SS-ribbon) are created mainly owing to the competition in the edge structures, finite-size confinements, and asymmetry of chemical bonds in the tetrahedral lattice or chemical modification. By applying uniaxial tensile or compressive strain, it is possible to modulate the physical properties of pSiC2NRs, which subsequently change the transport behavior of the carriers. Interestingly, the pentagon network of SS-pSiC2NRs is still maintained, but the bond length along the strained direction undergoes a large change. The electronic band structure and bandgap are strongly affected by the uniaxial compressive strain. The evolution of bandgap versus strain is linear. The I–V characteristic of SS-pSiC2NR seems to be more sensitive to compressive strain than stretch strain. The ultrahigh and strainmodulated carrier mobility in monolayer penta-SiC2 may lead to many novel applications in high-performance electronic devices. Furthermore, the unusual properties of the pSiC2 nanoribbons render them with great potential for applications in optoelectronic devices, especially in photovoltaics.