Frame Lake is irregularly shaped, with a northern section and a southern section along a north-northeast to south-southwest axis approximately  long, connected by a narrower central passage midway along its length where a wide peninsula extends from the western shore and an arm extends roughly  to the east, curving northward. At their widest shorelines, both sections are roughly the same distance apart. Five small islands are located within the lake, three in the northern section and two in the southern section. Its total surface area is .
The lake lies at an elevation of . Surrounding terrain is gently undulating, with some of the small hills nearby cresting as high as  and one of the islands rising to . Two unnamed streams drain into the lake south of the peninsula on the western side. The northerly of the two rises from drainage ditches surrounding the runways at Yellowknife Airport  to the west, draining Robinson's Pond on the way to Frame Lake; the southerly has largely been channelized, draining Range Lake  to the west, itself fed by a stream of similarly short length flowing into it from the west.
Surrounding terrain, as well as that of the islands, is primarily taiga forest, amid mostly bare outcrops of Canadian Shield bedrock typical of the Yellowknife area. Bare rock predominates on the shoreline, except for some shallow bays with weed beds. On the eastern shore, near the southern end of the lake, is an overgrown sandy area called McNiven Beach, after the city's first mayor.
The developed areas of Yellowknife form a "V" around the lake. On the eastern side, and the southern shore of the arm, is New Town, the citys modern downtown. Public buildings such as City Hall, the Royal Canadian Mounted Polices local headquarters, and the Canadian Forces Northern Area Headquarters Yellowknife are situated along the south side of the arm, their associated lawns coming almost to the edge of the lake.
South of City Hall along the lake shore is Somba Ke Park, open space with the only totally developed portion of shoreline. Beyond it, the taiga and bedrock buffer the lake from the city, except for the dead end of residential Matonabee Road. The Frame Lake Trail, a partially paved pathway  in length, closely follows the shoreline past an extensive area of forest. Just south of McNiven Beach is a recreational facility with an arena and pool, again close to the waters edge.
At the south end, another residential neighborhood comes near the lake, after which a rocky area buffers Stanton Regional Hospital. Commercial strip development along Old Airport Road also comes close, and the road itself runs alongside part of the lakes southwestern shore for . After it curves away to the west, the northwestern side and northern end of the lake are all taiga and bedrock between Frame and nearby Robinsons Pond and Jackfish Lake, with just the trail alongside.
Amid a park-like setting on the northeastern corner of the lake, and the northern shore of the western arm, stand two other large public buildings: the Prince of Wales Northern Heritage Centre and Northwest Territories Legislative Assembly Building. The two are connected via paths and driveways through the intervening taiga and bedrock. A causeway carries the Frame Lake Trail across the tip of the arm, where the Northern Frontier Visitor Centre overlooks the lake.