<p>This study developed a novel kind of ferromagnetic multi-principal element amorphous alloys (MPEAAs), which exhibited high thermal stability, enhanced glass forming ability (GFA), acceptable soft magnetic property, good microhardness, and preferable corrosion resistance by adding the rare-earth element Y with its content ranging from 0.5 to 4 at.% based on the (Fe_1/3Co_1/3Ni_1/3)₈₀Si₆B₁₄ multi-component amorphous alloy via the high-speed melt-spinning method. From the microstructural characterization analysis, apart from the 0.5 at.% Y-added alloy, the other four samples exhibited fully glassy state, and all ribbons presented smooth surface. It was found that the controlled Y addition could efficiently increase the thermal stability, GFA, and corrosion resistance of MPEAAs. With the addition of Y, the self-corrosion current density decreased from 3.017 to 1.452 µA·cm⁻². The glass transition temperature (<i>T</i>_g) and first onset crystallization temperature (<i>T</i>_x1) increased from 655 to 720 K and from 695 to 790 K, respectively. However, increasing the Y content could deteriorate the soft magnetic performance. The saturation magnetization (<i>M</i>_s) decreased from 104.3 to 83.5 emu·g⁻¹, and the coercivity (<i>H</i>_c) increased from 12.2 to 26.7 A·m⁻¹. Besides, the Vickers’ microhardness of all specimens could reach 753 HV_0.5 in the melt-spun state and remained above 690 HV_0.5 after corrosion.</p>