In one aspect, provided herein are naturally occurring and recombinantly produced avian paramyxovirus (APMV) (e.g., an APMV-2, APMV-3, APMV-4, APMV-6, APMV-7, APMV-8, and APMV-9 strain) and uses of such APMV for the treatment of cancer. In particular, provided herein are methods for treating cancer comprising administering a naturally occurring or recombinantly produced APMV-4 strain to a subject in need thereof. In another aspect, provided herein are recombinant APMV comprising a packaged genome, wherein the packaged genome comprises a transgene. In particular, described herein are recombinant APMV (e g., APMV-2, APMV-3, APMV-4, APMV-6, APMV-7, APMV-8, and APMV-9). In another aspect, provided herein are methods for treating cancer comprising administering a recombinant APMV (e g., APMV-2, APMV-3, APMV-4, APMV-6, APMV-7, APMV-8, and APMV-9) to a subject in need thereof, wherein the recombinant APMV comprises a packaged genome comprising a transgene. In particular, provided herein are methods for treating cancer comprising administering a recombinant APMV-4 to a subject in need thereof, wherein the recombinant APMV-4 comprises a packaged genome comprising a transgene. In specific aspects, the use of APMV serotypes other than APMV-1 (such as described herein, in particular AMPV-4) to treat cancer is based, in part, on the similar or enhanced in vivo anti-tumor activities when compared to oncolytic NDV La Sota-L289A strain.