Quick answer: for most of the 20th century, cheerleaders wore everyday footwear: saddle shoes or flat canvas sneakers with high socks. Sneakers took over from saddle shoes from the 1970s, and canvas Keds with slouch socks were a classic look in the 1980s and 1990s. Dedicated cheer shoes - light, grippy and built for stunting - arrived as the sport became more athletic, and competition rules now require soft-soled athletic shoes.
Saddle Shoes and Canvas Sneakers
From the early 1900s through the 1950s and 1960s, cheerleaders typically wore saddle shoes - leather shoes with a contrasting "saddle" across the middle - or flat canvas sneakers, with high white socks. At Ohio State in the 1950s, for example, the women's uniform included white socks and saddle shoes. That was fine for crowd-leading, which involved little more than chants, motions and simple jumps.
Sneakers Take Over
From the 1970s, sneakers replaced saddle shoes as cheer became more athletic. Canvas Keds - first made in 1916, and one of the first mass-marketed canvas sneakers - became closely associated with cheerleading. From the mid-1980s to the mid-1990s, white Keds worn with thick "slouch" socks were a classic part of many squads' uniforms.
Why Dedicated Shoes Became Necessary
As cheer added more tumbling and, above all, more stunting, footwear had to do more. Flyers needed shoes that bases could grip securely; tumblers needed cushioning for landings; everyone needed a light shoe that wouldn't weigh down jumps. Fashion sneakers and general trainers weren't built for that combination.
The Modern Cheer Shoe
Athletic footwear makers responded with shoes designed specifically for cheer: very light, low to the ground, flexible, with smooth, narrow sides that bases can hold, and some with grooves or pockets in the sole for bases' fingers. Most teams now wear matching white cheer shoes chosen by the gym. See What Are Cheer Shoes?.
The Rules Today
Competition rules now spell out what can be worn. Under the USASF All Star Cheer Rules, athletes must compete in soft-soled shoes with a solid sole - dance shoes, boots and gymnastics slippers aren't allowed.
A Note on Dates
Exact dates for footwear trends varied between schools and regions, and fewer sources cover shoes than other parts of the uniform. Where we give dates, they reflect the sources listed below.
Sources: Cheerleading uniform (Wikipedia); Of Pompons and Human Pyramids (Ohio State University Libraries); Keds (Wikipedia)