Tamsin is a moderately popular girls' name in England & Wales, ranking #344 in 1999 with 94 recorded births. The name reached its all-time peak in 1996 with 137 births ranking #271. Since 1996, the popularity has decreased by 31.4%. In 1999, approximately 1 in every 2,997 girls born was named Tamsin. FALLING Recent data shows the name is currently falling.