Simulated genomes with pre-defined and random genomic variants can be very useful for benchmarking genomic and bioinformatics analyses. Here we introduce simuG, a lightweight tool for simulating the full-spectrum of genomic variants (SNPs, INDELs, CNVs, inversions, and translocations) for any organisms (including human). The simplicity and versatility of simuG makes it a unique general- purpose genome simulator for a wide-range of simulation-based applications.